Facebook Kids Messenger is decent (for all the reasons you mentioned), however, I am pessimistic about it being genuinely appealing to kids. It's staying alive because middle-aged parents are forcing it on their children - they are the consume and decision-maker. My experience is once kids are allowed to make their own decisions they quickly move away from it.

Of course once kids are allowed to make their own decisions, the main value of FKM is gone. (parental controls and such)

So it isn't the best example, and it isn't really facebook per se but more of a separate product, but still.... it is squarely aimed at kids that aren't old enough to make decisions for themselves, by design.

It's a pity I distrust Facebook so much that I'd never give this a try (my kids simply don't social except sorta on Nintendo).

My kids connected with their friends through outside activities properly masked up.

Outside gatherings were banned for a while here, so even masked groups in public parks were not feasible.

Ugh. Sorry to hear that. IMHO the damage done to the kids here is worse than the risks they would face from the virus.

Kudos to you for doing what you can to keep your kids connected socially.