every provider who supports aliases. like [email protected] where everything after the + is exchangeable. so you can use a ‘different’ mail for every service you use and just block where spam comes from via the alias.

Maybe have a look at the tool from 0&0 called “shut up windows 10”

Nothing realy exept licencing

Maybe consider using forgejo (gitea fork used by codeberg)

And i do think, some changes would be needed but nothing big, also it wouldnt ne activated by default.

Cellphone network calls / texts aint secure at all. If you want to communicate in a secure way you need to use another seevice/app.

Many stated matriy as selfhostable service and i totally agree. Signal/Threema are also good options If you dont want to selhost.

I second matrix. Its also federated and has mutible clients. But like lemmy under development (but more advanced in the development process)