Snowden's revelation of US surveillance infrastructure more than 10 years ago doesn't really change much of people's perspective about privacy. Should be no surprise that people are still on facebook platforms.

I'm not from US, probably most of my friends don't know about Snowden, surveillance capitalism, and such. Some other people are already struggling enough with their daily shit to care about their online privacy.

And those infrastructure is also most useful to fight against journalist, US adversaries/critics, etc, than ordinary people.

Timing first, friction later: Whatsapp was first, it extended like wildfire in Latin America before the 2014 buy in by Meta. I attribute it to the ease of configuration: you didn't need an email, it was just your phone number, and then all your contacts were reachable. It didn't lose traction even when it changed from free app to "free for a year". Friction came later, Telegram gained some ground but it was very niche, my friends that were in CS were using it "for the bots and the stickers" but you needed to invite your contacts to use it and it didn't make sense if they already had Whatsapp. Later, more and more businesses started using Whatsapp to chat with customers and eventually it became the default.

Whatsapp was great and everybody used it before Facebook bought it. It was 1€/year subscription.

Now that Facebook bought it, there's no way of choosing an alternative. Only "nerds" care about it being owned by Facebook. And "nerds" don't have enough social power to say "if you wanna talk to me, you have to use this other app", they'll just stop talking to the "nerd".

Exactly.
Step 3 is where you have cause to get upset, and complain. Not there yet.

Honestly Lemmy and Piefed looking like Reddit from 10 years ago is a feature, not a big, to me.