SANTA CLARA, Calif. — For the past 21 months, the San Francisco 49ers’ movers and shakers have waited for the team to storm back and reclaim its swagger, as if that fourth-quarter collapse in Super Bowl LIV and the ensuing onslaught of disappointment could be written off as an aberration.

As we approach the midpoint of another sobering season, it’s time to consign the 2019 Niners to the memories folder and be honest about the current state of the franchise.

Yes, the 49ers still have legitimate stars like George Kittle, Nick Bosa and Fred Warner, and head coach Kyle Shanahan and his assistants can still scheme it up with the best of them.

No, they are not a good football team — and that sordid state of affairs doesn’t seem likely to change anytime soon.

After getting embarrassed at Levi’s Stadium on Sunday by a weakened Arizona Cardinals ensemble that played as though they were the desperate ones, the Niners awoke Monday morning at the bottom of the NFC West and sinking fast.

Theoretically, they still have a chance to turn things around and mount a potential playoff run, beginning next Monday night at home against the rival Los Angeles Rams. Realistically, they’re teetering on the edge of irrelevance and running out of chances to make it right.

“Yes, it can be done,” center Alex Mack said as he left the field following Sunday’s 31-17 defeat to the division-leading Cardinals, who executed the smackdown with stars Kyler Murray and DeAndre Hopkins watching from the sideline. “But it’s got to happen soon — like, very soon. We’re running out of time.”

Mack, who signed with San Francisco last March, wasn’t around two seasons ago when the Niners rolled to the NFC championship and held a 10-point lead over Patrick Mahomes and the Kansas City Chiefs with half a quarter to play in the Super Bowl. Since that time, the 49ers are 9-16, a prolonged stretch of futility that can no longer be blamed exclusively on injuries.

They’re now at the point at which wounded pride is also a factor. As Warner, the team’s All-Pro middle linebacker, said last Thursday in an interview at the team’s training facility, “I’ve kind of put (2019) behind me, and I think the team has as well. You obviously want to reflect on the times we were successful and we did things the right way, to see, ‘OK, how could we apply that to the situation we’re in now?’

“But we’re the 2021 Niners, and what’s reality? Reality is we’re 3-4.”

Make that 3-5, and count most of the 59,012 fans who witnessed Sunday’s debacle in person among the non-believers.

For them — and especially for the men in red-and-gold uniforms — it was a punitive reminder that life comes at you fast in the NFL.

Heading into the 2021 season, the 49ers’ locker room was filled with players who believed they were poised to rejoin the ranks of the league’s elite.

“I think a lot of us looked at this roster and kind of saw where it stacked up with the NFL,” Pro Bowl left tackle Trent Williams said Thursday, “and it did stack up near the top.”

Early returns were promising: After opening the season with road victories over the Detroit Lions and Philadelphia Eagles, the Niners were 37 seconds away from closing out a dramatic comeback victory over the Green Bay Packers. Then Aaron Rodgers did Aaron Rodgers things, setting up Mason Crosby’s game-winning field goal as time expired, and the 49ers’ ills began — and no, unlike the Pack’s star quarterback, they have not been immunized.

Ending a four-game losing streak with a 33-22 road victory over the Chicago Bears on Halloween provided a flicker of hope; Sunday’s sloppy effort against the Cardinals, their eighth consecutive home defeat (five at Levi’s, and three at the Cardinals’ home stadium, where the Niners were forced to relocate in 2020 because of local COVID-19 restrictions) all but extinguished it.

First-half fumbles by Kittle, the prolific tight end who’d missed the previous three games with a calf injury, and second-year wide receiver Brandon Aiyuk killed San Francisco drives, and the Cardinals exposed the 49ers’ defensive deficiencies all afternoon.

In 2019, the Niners’ defense was frequently dominant, and Bosa, then a rookie, was part of a menacing front that made opposing quarterbacks quiver. On Sunday, against all odds, 35-year-old quarterback Colt McCoy (22-for-26, 249 yards, one TD, no interceptions) and running back James Conner (21 carries, 96 yards, two TDs; five receptions, 77 yards, one TD), a Pittsburgh Steelers castoff, resembled Joe Montana and Roger Craig in their primes.

“Good teams have an identity,” one veteran player said Sunday evening. “Ours — what is it? We’ve just got to keep pressing to find it.”

How did things get so dismal, so rapidly? In retrospect, the decline began in the weeks after Super Bowl LIV when Shanahan and general manager John Lynch chose to keep one expensive defensive lineman (Arik Armstead, who the Niners signed to a five-year extension worth up to $85 million) and part ways with an even more expensive one (DeForest Buckner, who was traded to the Indianapolis Colts for the 13th overall pick in the 2020 draft). The Niners then moved down one spot and drafted defensive tackle Javon Kinlaw as Buckner’s replacement.

Kinlaw, who had knee tendinitis coming out of South Carolina, struggled with related issues late last season and during the first part of 2021, ultimately going on injured reserve and undergoing reconstructive surgery to repair his ACL. Buckner has missed just two games in six seasons and remains one of the league’s top defenders. Throw in the absence of edge rusher Dee Ford, who has been plagued by chronic back and neck issues since 2020 and was placed on injured reserve last Saturday, and the Niners’ current defensive front is far from elite. Armstead, who had a sack and 10 tackles against the Cardinals, has played at a high level, but Buckner has proven to be more of a difference-maker.

Another dubious decision: The organization put its faith in veteran Jason Verrett as its top cover cornerback. Verrett, plagued by knee and Achilles issues, played only six games from 2016 to 2019 but bounced back to have a strong 2020 season. He suffered a torn ACL in the season-opening victory over the Lions, and the 49ers secondary has struggled ever since.

While first-year defensive coordinator DeMeco Ryans has been the target of some criticism, Shanahan — both as head coach and offensive play-caller — is even more under siege. Barring a turnaround, he’s headed for his fourth losing season in five campaigns, and the Niners have lacked offensive punch in 2021.

There have been some hopeful signs, including the recent emergence of Aiyuk, a first-round pick in 2020, as a complement to productive wide receiver Deebo Samuel. Against the Cardinals, Aiyuk had six catches for 89 yards and a touchdown. His second-quarter fumble at the Arizona 7-yard-line, after leaping to catch a high pass from Jimmy Garoppolo (28-for-40, 326 yards, two TDs, one interception), was an obvious mitigating factor.

“Aiyuk is really, really starting to come into his own and understand how to be a professional,” Williams said last week. “The coaching is finally starting to get to him. I think he understands that they’re only coaching him hard because there’s something inside of him that a lot of people don’t have. The only way you bring it out is to push that person. To me, I think he’s starting to get it, and I think his play resembles that.”

And what of Jimmy G, a man whose initial promise earned him the nickname “Jimmy Jesus” during Shanahan’s first season as head coach? Garoppolo remains the Niners’ starter — and, realistically, the quarterback who gives them their best chance to win in 2021 — but the clock is ticking.

Last March, when the 49ers sent three first-round picks and a third-rounder to the Miami Dolphins to land the No. 3 overall selection in the 2021 draft, it was obvious that Shanahan desperately sought a franchise quarterback. When he chose North Dakota State’s Trey Lance, a hyper-talented and glaringly intelligent player with a very limited body of work, Shanahan clearly was playing the long game.

A week into training camp, coaches believed Lance had grasped Shanahan’s intricate offense so quickly that they might be able to accelerate the plan and start him right away. Then he leveled off, lost confidence and clearly became a less appealing option than Garoppolo — who had his best training camp as a Niner, by far— though Shanahan and his assistants were excited about the prospect of using a “Trey Lance Package” to keep teams off balance.

Lance’s sprained left knee — suffered during the 49ers’ 17-10 defeat to the Cardinals in Arizona four weeks ago, when Garoppolo was out with a calf injury — made coaches less excited about summoning the rookie for cameo appearances. Yet realistically, if the Niners’ downward spiral continues, there will soon come a point at which keeping Lance on the bench no longer makes sense.

The challenge, for Garoppolo and for the Niners in general, is to stave off that pull-the-rip-cord moment and find a way to stay in the mix.

If 2019 seems like an increasingly distant memory, the hope is that the 2021 season can still be redeemed, however faint that possibility might seem to be.

“Honestly, man, I cannot put my finger on it, but we cannot lose hope right now,” said the veteran player, who asked that his name not be used. “Even though this is bad — I mean yeah, very bad — it’s still a salvageable place we’re in. We have talent; we’ve just got to find a way to put it all together, somehow.

“And I believe it can start this week. Shoot, it has to.”