Don’t assume everyone shares your ‘values’.
Apply some of this yourself first please. You've hit the nail on the head on your own without even realising it. Different families, different values.
To answer your initial question, what do you think parents should have done in March 2020? Pull the kids out of school indefinitely, because 'pandemic'? These kids, neglected or not, have the right to as smooth an education as possible. If anything, you could argue boarding schools would achieve that better than day schools. I don't understand what you think the solution should have been, you can't indefinitely pull the child out of school, without disrupting, in many cases, the whole family. I was living on a military base in, I don't know, Northern Cyprus (no idea if there are military bases there), my partner was deployed every X weeks and my life lacked any kind of consistency, the last thing I could've done was pull my kids out of school, organise an international relocation in the middle of the first wave when flights really stopped - now there are some at least - find new schools, get the kids adjusted to a new life, all for the sake of a pandemic that will most likely affect 2-3 of their 12 years in education.
Are you also someone who thinks people demanding travel restrictions to be eased so they can visit their families abroad, should have thought about global pandemics before moving to a different country? Or they should have moved back/have their relative come back as soon as the pandemic started?
It's not as easy as pulling your child out of a school in another continent, or relocating/uprooting your whole family when things get tough. I'm sure none of these international boarders' families are happy with the situation, they must miss their children so much. However, life is more complicated than you think.