I think the only thing that was really curtailed was my sons took a few months off of karate? A lot more traumatic was probably mom having to sleep in a hotel for a few nights because she got inadvertently exposed to COVID as nurse (when we really didn't know how dangerous things were), or me having to camp out in my folks' motorhome for a week because I was at the tip of the spear medevac-ing people out of camps in the arctic. I know that was scary for my kids because they told me it was.
Them not being able to have playdates being some generational trauma is nonsense. What wasn't nonsense was watching aunts and uncles die from a pandemic that we did next to nothing to fix in America until the vax came out. Also, I would not be surprised if there aren't some cognitive effects to COVID. Despite being very careful, we got it too. Everyone had it here. That probably ain't good for kids' development.
But mostly, I think it's the phones that are having the biggest impact on social development and probably on learning too. Read this paper: https://www.nber.org/papers/w35310
If people like doom scrolling more than they like screwing, it's probably not unlikely that they like doom scrolling better than studying.
Here in Illinois it was over a year, possibly two in some places. The schools didn't return to in-person right away after the government mandates were lifted.
Edit:
> But mostly, I think it's the phones that are having the biggest impact on social development and probably on learning too.
Please re-read the comment from the other person you originally replied to.
(2nd edit: removed something based on a misread)