If everyone starts using signal I'll go along. But they won't so they're isn't any point. I'll still need WhatsApp so they'll keep tracking me. Signal also has poorer group chats (no subtopics for example) which I use a lot.

And if they get big quickly they'll run out of funds and will have to make similar decisions. They're not going to continue being funded by big tech bros like Brian Acton's 50M$ if their costs balloon. For me to actively promote it and use it without a big userbase, it will have to be so open that I can run my own server, like email. I do run matrix for that reason. I like ownership of my services and I'd rather contribute to the network than donating.

Ps: if he really wanted to help accessible safe communications he shouldn't have sold WhatsApp.

I see more in solutions to thwart their tracking. Such as using a matrix bridge, which I do. I do the same with search, I use a meta-search engine to remove tracking and ads. I can also customise it to my wishes that way.