By having each school's IT setup a separate server

School's have IT. It isn't always competent IT (I speak from experience), but clear instructions from up high can lead it

Or, you can flip a switch and enable Zoom, Google, or even Microsoft.

IT people are hammered right now, nobody has time to futz around with some random oss tool that will further stress overutilized remote infrastructure.

While I believe this will work for NYC, I'm not sure how it'll work for Pumpkintown TN

Pumpkinland, TN will use Zoom. It’s exponentially easier, except for older kids already using Google Classroom.

That's kinda my point. That the IT in a major city can use a custom system but that discludes a lot of people. I would wager that most schools don't have a decent IT department. I know that when I was in high school they weren't great and I grew up in a fairly affluent area. Not everyone has the ability to "roll their own"

It probably isn't, but one could hope.

Edit: If I'm honest I'm not even sure how meet.jit.si can function at it's current scale. Especially because I've found no way to send them money.

I think it hosts about a thousand rooms on a lowly single core - absolutely unbelievable in the age of kubernetes, I know... Given that, it needs bandwidth (but Zoom needs that as well for a 30 participant video conf...) and this seems paid for by the consulting company upselling it to companies.