Matrix clients aren’t great
IMO the main advantage that Matrix-Element has for normal users is the branding: Element is Element on the web, Android and iOS. (Snikket is trying to do the same for XMPP though)
Matrix is too difficult for “normal” people
Agreed. Simple user+password login to a hosted (non-matrixdotorg) server takes 5-6 pages to click through.
Matrix public rooms have a CP problem
I was spammed with racist copypasta on XMPP once too. But being in large Matrix chats guarantees being invited/messaged.
...Matrix also pisses metadata to any server it federates with, including matrix [.] org
Replication+sync is a strange decision for chats. It sort of makes sense for slower fediverse posts, but creates a lot of strange scenarios and privacy issues with chats. Also, matrixdotorg is used for key backups and vectordotim is used for integrations IIRC.