F-Droid

WhatsOpen lets you start whatsapp conversations without needing to give meta access to your contacts. Although you still need to have the official whatsapp app and an account there.

Unfortunately you have to create an account and provide phone number to WhatsApp for communication with your family.

You can disable cloud backups, set auto destruct message timers, not use metaAI and not put any extra info, but not much else to mitigate. At least message or voice content is end to end encrypted, but Meta sure collects a lot of metadata.

Also if you are on grapheneos, you can set up contact scopes, to only include people you communicate with on the service.

One rather complicated method of accessing whatsapp:

• Install the whatsapp app within an android emulator on your computer (such as waydroid).
• Create an account using a throw-away number (I got a £10 pay-as-you-go sim just for that, though you will need to put the sim in a phone to get the verification sms).
• Access whatsapp on your computer or phone through web.whatsapp.com (there seems to be an f-droid app for that too) (They recently added support for voice+video calls).
• You will need to boot up the android emulator every 2 weeks to sign in to whatsapp web.

Don't let your family set your standards, if they don't have any.

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.

what free droid apps can do simply that, not needing for me to provide a phone number or my current location / country?

There's an endless list, but here's a few:

• SimpleX
• Briar
• Cwtch
• Jami
• ArcaneChat/DeltaChat
• XMPP
• Matrix
• Zulip
• Fluxer
• Chatto
• BitChat

How would that even work? You need an account to use a messaging app.