don’t know if this is an appropriate community
I don’t particularly like this application, but my whole family uses and they simply won’t use any foss alternative I’ve proposed so far.
I’m even thinking about joining them.
I only need audio, no video calls, no file transfers.
ETA: what free droid apps can do simply that, not needing for me to provide a phone number or my current location / country?
No, you can’t. And there are messaging apps available on FD. The problem is not so much their availability there but whether or not the people you want to talk to also use them.