Comment by bsimpson

I spent a dozen years in SF, where my friend circles routinely used Signal. It's my primary messaging app, including to family and childhood friends.

I live in NY now. Just today, I got a message from a close friend who also did SF->NY "I'm deleting Signal to get more space on my phone, because nobody here uses it. Find me on WhatsApp or SMS."

To a naïve audience, Signal can have a stigma "I don't do anything illegal, so why should I bother maintaining yet-another messenger whose core competency is private messaging?" Signal is reasonably mainstream, and there are still a lot of people who won't use it.

I suspect you'll have an uphill battle using something even more obscure.