I have one page with my full history of text messages, full transcription of all voice messages, contacts information connected with every number, and I can search everything. I can configure which of my phones ring.

And, possibly most importantly to me right now, my current phone has only a data connection and I make and receive calls using the Voice app. I think SIP eats too much battery and data and doesn't work well for wifi<->lte switching, but it's been a long time since I used it much.

I'm not sure what the OP does, but at least for me I find myself chained to Google Voice for SMS 2FA use because it's basically the only phone number provider that cannot be exploited with a sim swap attack (same deal with Google Fi). And while I don't necessarily trust Google, their account security is leagues ahead of anyone else imo.

I previously looked at jmp.chat but they didn't really inspire confidence on the security front.