I'd use something that's truly decentralised but signal is just another walled garden like WhatsApp. Just one that promises to behave better. But what's a promise worth these days?
A decentralised network would mean a guarantee that they can't do anything bad. I'll take that over promises and good intentions any day.
I don't care about the masses. If signing up for a matrix account is too annoying for them they don't really care about privacy anyway. After all it's the same they have to do for any online shop. Just create a username and password. Somehow it's not a problem for the masses if they wanna order a phone charger but for matrix it's suddenly 'too complicated'?