What better alternatives do we have? Not tying my account to a phone number, but rather saving thirteen words, is exactly the UX I've always desired. I don't even need privacy, but I hate losing things when I inevitably lose my phone number.

Ricochet (chat via Tor .onion circuits): https://www.ricochetrefresh.net/

Tox (if you're addicted to phones): https://tox.chat/

>What better alternatives do we have?

Set up your own XMPP or Matrix server and only expose it via Tor.