Most of what causes low performance in schools is beyond the ability of schools to address. It's why we keep trying reforms and they don't do much—and when they appear to, it usually turns out, in the long run, to have been dumb luck or number-fudging, either intentional or because the people involved don't know how statistics work. "Bussing" is within the scope of schools (kinda...) and that worked—it's got little company, in the things-that-worked category—but practically everyone hated it, so that's out.
Properly fixing all this either means launching massive social programs that have little to do (directly) with schools and will likely take years to really bear fruit, in terms of educational outcomes—good luck with getting that done in the US—or letting schools do things we've decided (largely for good reasons) they aren't permitted to, like simply declining to serve a whole lot of kids.
(separately, yes, Covid was an absolute disaster for education and we'll be dealing with that damage for generations—that's just true, and I think much of society's kinda in denial about exactly how bad it was—but it certainly wasn't because teachers were, in general, kicking back and having a great, relaxing time for that couple of years; I also think there's a set of people who credit teachers with a much greater degree of influence on school policy than they actually have; further, I think these discussions can be difficult because the facts on the ground re: union power and such vary wildly across the country, though, I'm pretty sure, without strong and clear correlation to educational outcomes—my state has very weak teachers, on that front, but still has plenty of schools posting terrible outcomes)
As for the baseline-resetting, a lot of these measures are, for good reasons, concerned with relative achievement—achievement year-over-year, not absolute achievement, i.e. they're looking to measure growth—so it's a little hard for me to tell if that's a totally normal thing being spun as bad, or in-fact bad. Could be the latter and it's every bit as bad as you suggest, IDK, I've only a little familiarity with NY's achievement metrics. Your article leads me to believe it's the former, actually ("A scoring committee that reports to the Board of Regents said Monday that they must take into account the results of last year’s tests for students in grades three through eight to determine whether schools are showing improvement from year to year") despite framing the move as unusual/remarkable, though it's hard to be sure just from that source. School admin and state governments definitely aren't above screwing with those kinds of stats to make themselves look better, though—seen it happen, it's pathetic, and a dereliction of their duty to the kids, but it can be effective at achieving their ends of making it look like they're doing anything useful.