Yes, though only because it's a lot of trouble to set up today.
If it were completely commoditizated -- imagine one more button when setting up a new phone ("Choose where your data resides: Apple, Google, Facebook, Self hosted") and it was completely transparent then it would be used much more, especially if that's complemented by one of the nerds setting up e.g. a neighborhood sync server and everybody around knowing it and using it.
So yes, you are not wrong but the situation can change dramatically if ergonomics are improved. Which sadly most of the nerds never work on.