Honestly Matrix E2EE and federation is a bit like cryptocurrency (without going into all its other social problems).
It's clever, it's an impressive technical achievement that it works at all... and it completely ignores all the practical reasons why server-centric systems exist.
You don't solve Visa and Mastercard censorship with crypto, you solve it with payment platform diversity. And you don't solve Discord with Matrix, you solve it with something with a design closer to IRC or XMPP.
(Reposted & lightly edited from a DM reply I wrote)