So because other organisations use email for which it isn't really suited, you "banned" email?

Also, another point to think of: when one of those tools you use go away, how do you salvage your progress / information? It's not bad to try to minimize email usage, but I do find it bad to rely on external services for such critical stuff (meaning the documents with information).

Why not use a selfhosted option? That way you can be sure that it won't go away anytime soon.