The getting people to use it.

Took me months after issueing my friends and family accounts for most of them to get the concept and install something to log into (I still get complaints about Element, and thats one of the nicer ones).

For mobile apps, if its not seamlessly integrated into their existing accounts or they have to remember a new password, you might as well have given them a bag of spiders.

The fact that every OS comes with pre-installed email client and everyone knows at least 3 free email providers but most people have no idea what matrix even is?

Those people have no idea about Signal either.

for me, it’s that it breaks randomly. all. the. time.

With element, it was constant across two different homeservers I tried. Either logging me out, or just randomly unverifying my client and failing to decrypt messages.

with fluffychat, it’s been more stable, but recently it’s taken to logging me and a friend of mine out at random just like Element. After logging back in, it constantly tells me there’s an error fetching the notification (even though I’m not launching from a notification) due to the account not existing.

The protocol feels incredibly fragile, since it seems every implementation trips over the same footguns, and it makes the user experience horrible.