I want to say Stoat... However I'm struggling to even create an account... And I have much more patience than my less-savvy friends.

If like me, you care less about servers and the "social media" aspect, and are just searching for group messaging, voice/video chat with screen-sharing capabilities, then Signal Desktop will suffice. That is what I'm preparing to suggest. You can now also sign up without a phone number which is a bonus.

That should work fine, at least until Stoat matures. As a bonus, doubles down as a replacement to Whatsapp: two birds, one stone.