I've always known that SMS are not encrypted and that they are not the safest way of communication. I tried using signal with others all on graphene os, but all phones seem to have their battery drained heavily due to graphene having to run signal in the background for instant notifications.
What do you all use as a safer daily alternative to SMS for mild sensitive info that doesn't drain the battery?
Preferably: trusted, privacy respecting, free, bonus if FOSS
Anecdotally, I have found Conversations (XMPP federated chat) is better for battery life on GrapheneOS than Signal.
The onramp is more complicated. I learned the hard way that uptime history is the only aspect I really care about when choosing a server.
All XMPP accounts on all XMPP servers can talk to each-other, as long as both user's home servers are up and running.
Oh, and you need to turn on encryption - it is optional. OMEMO encryption is widely supported and good enough for casual chat security.