Yeah I have it and use it for a couple of people (that I know online) but none of my irl friends do... I still get people eventually emailing me saying "I've sent you loads of messages" only to find they use WhatsApp... And despite me requesting a data delete several years ago, Meta still hold that and show me as a contact on there. I had Briar and another one too but there was literally only 1 person I could message.
If I were a rich man I'd get some legal help on it but life's too short...