Simplex is really easy to install and use, unfortunately it’s still kinda buggy, specially with public relays, I personally don’t mind buggy, I’m willing to make sacrifices for the same of freedom and privacy.

I just keep a second chat app as a failback so I can send them a message saying “ur simplex broke again, pls restart”

Xmpp has been stable for decades, tho I guess otr/omemo is hard for family to install, also doesn’t support e2ee calls (or rather, it does, but it’s complicated). But I haven’t used xmpp in a long time.