As seen with Signal Advocacy as well.
I will play devil's advocate, it is not necessarily that people have bad excuses, most of the time it just hard to break from habits. It doesn't help either that in the case of digital privacy, most people don't give a fuck. Tech companies know that people prefer convenience.
The only way I see how people will migrate to more ethical services like Fediverse and Signal is if enough people are convinced to go, that it will start a FOMO sentiment on to each person. That is the real boulder we are rolling up the hill.