UK here. Most people I work with will have Signal or Telegram. However my kids and the parents groups and schools all use WhatsApp.
None of them could get their friends to switch from WhatsApp. Nobody gives a shit at all about Meta and their dodgy data practices. Convenience is king. "aLL mY frIEnDs aRE oN WHatSaPp!"
They will literally be excluded if they don't use it.
Super-frustrating and makes me feel pretty helpless tbh.