The problem is the kids not getting to decide. I know 100% if I were a kid in such a situation I would not wear a mask ever to the extent I'd get sent home. I'd demand a remote education (such as K12), homeschooling, or at the very least to be put in a private school district or other school district that doesn't require masks. Masks just make life miserable.
I'm not going to be one of those that say masks are completely useless because that isn't true either. But even as someone who literally contracted 28 upper respiratory viruses (colds) in 4 years in high school, and was sick with a URI roughly 40-45% of the time. I don't know, but I was probably one of the hardest hit high school kids in San Antonio and in the country in terms of sheer number of separate times I got sick. I wouldn't trade the other 60-65% of the time where I was for wearing a mask 100% of the time, for the world, even if it meant never catching a cold, or say only catching a cold 2 or 3 times in 4 years instead of 28 times.
I was high school valedictorian but I also was the type of kid who couldn't stand being told what to do and I wouldn't. I wasn't little mister goodie two-shoe. I was suspended once and put in in-school-suspension six times. And I wouldn't have wanted it any other way. I believe students should have the right to choose.
As far as the childhood anxiety, depression, etc from loneliess... you are correct on that account, but having to go and socially interact with a mask covering your face 100% of the time is honestly worse than no social interaction. You take away the element of looking good and feeling good. You end up with miserable social interaction. Out of the three choices, if you can't have fully social maskless interaction due to a pandemic, it's better to just interact online through webex/skype/zoom/MS teams calls.