One big thing you need to think about is accessibility. This is something that came up in a conversation with a local representative in the UK - for children in public schools it is a requirements that any technology have good accessibility and not leave anyone behind. And accessibility tools on linux are, suffice to say, not great. Especially when compared with those on other closed systems. My local government ended up going with iPads for kids in schools, and the accessibility tooling on these was a factor in that choice.

Indie games are good, but if privacy is a concern be careful of any game developed in a big engine like unity. My firewall pings a warning every time I launch a unity game because they all send analytics data back to unity. If it’s single player and you block all outgoing connections by default, you’re fine though.

Can I get paid a billion dollars to do nothing?

Those other services are not great but they are at the very least not actively promoting AI-generated child abuse imagery. It’s an incredibly low bar, but they do pass it.