I'd want to hear more about this on a global level, but there's many many accounts on how children in schools became more unrily and apathetic in class post COVID. As well as this rising narrative on treating teachers as "babysitters" more than educators. I haven't heard as such in other countries.
Doesn't mean it hasn't happened elsewhere, but that may be a cultural issue due to many of the social safety nets that exist in other countries simply not being a thing in the US.
There have definitely been problems post covid in the UK - a huge increase in mental health issues for a start, and a definite effect on academic achievement (exams were made easier for a few years afterwards to offset it). IMO it accelerated existing deterioration rather than doing anything new, but it did have an effect.
The government certainly seems teachers as babysitters to some extent. There has been a push for more time in school, from having breakfast at school to more after school activities. More parenting being taken on by schools (I just read about "supervised toothbrushing" in schools on .gov.uk).
How well schools coped with it varied too. My older daughter's school (a well funded sixth form college) had relatively good IT, enough laptops to give them to kids who did not have computers at home, headsets and cameras for teachers etc. My younger daughter was home educated so it was easier to adapt but she still missed out on quite a lot of things, or had to do them online instead of in person and while she came out of it OK, its must have done some harm.
Breakfasts aren’t provided as a form of babysitting. The prevalence of breakfast clubs in schools in low income areas should be a hint as to why they’re instituted. After school activities are more babysitting adjacent, but if parents can’t afford after school minding but really need to hold down a job, it seems like a great idea that also gets kids into sports or chess or whatever.
Why they choose to do it in school rather than providing parents with more money so they can afford to feed their kids is also a hint as to why they are instituted.
"if parents can’t afford after school minding but really need to hold down a job"
i.e. if you want to expand the workforce by providing child minding on the cheap through schools.
The references within and citations of this paper * are as good a place to start as any.
It's Australian and more specifically focused on Victoria, a state with some of the longest global lockdown periods, while more generally comparing to other global educational research on the pandemic effect.
No one paper has all the answers you seek, but a handful of nodes in an interlinked web might do the trick for you.
Doesn't mean it hasn't happened elsewhere, but that may be a cultural issue due to many of the social safety nets that exist in other countries simply not being a thing in the US.