alt Hacker News> Network effect is killer. "better" would include having more than 3 billion people already on it.
At one point people moved from something else to Whatsapp, and that happened before Whatsapp had 3 billion people on it. If it's good, early adopters will adopt it and want others to adopt it too, then it snowballs from there.
It has happened before, and as long as new regulation doesn't solidify Whatsapp/FB in their position, it can happen again :)
WhatsApp happened at a time when, in Europe, you paid for SMS.
WhatsApp allowed people to send SMS without paying, or rather, paying just once to buy the app, so it was instantly valuable if you just convinced your spouse or parents or a single friend to install it.
To overcome it now, you need a lot more effort (or rely on enshittification, which I'm sure will happen).