A mass exodus from Whatsapp created a great opportunity to change a whole landscape of communication tools, but seems it is already missed though. Instead of switching to wonderful self-hosted (rocket.chat, element) or even p2p serverless (briar etc) alternatives, millions of ex Whatsapp users stuck with yet another centralized USA-based messenger - Signal. Sad.
ahaha definitely understand your situation, my gf tried to convinced her relatives for a year.