https://xkcd.com/1102/
What I mean is that in Mexico, Brazil, and many other countries, WhatsApp is the de facto messaging standard. Businesses expect you to have it, restaurant ordering is integrated with it, etc.
In the US, we don't have anything except SMS/RCS.
If you’re not a nerd, signal is like a batlight for people doing stupid shit.
The user base pales in comparison to WhatsApp but it did double in the last couple of years.