Yes I am using Signal. It's just that most people around me are not on Signal. Trying to convince them to switch is useless (although I try). WhatsApp is not my first choice either.
My perspective is, pick one of the many overlapping channels we already share or don't bother me. I am not signing up to yet another spyware-of-the-month app in order to chase your fashion sense.
It's a trade off. In some cases not installing the messaging app du jour means being left out of group chats. If that's ok with you, then by all means, allow yourself to be excluded. But that's not ok with everyone.