1. Passphrases, additional to passwords, should not exist. Mainstream users don't know the difference. Matrix needs something like
https://en.wikipedia.org/wiki/Secure_Remote_Password_protoco....
2. Technical lingo like "verify other session" and some buggy emoji shenanigans confuse people. The only passable device linking, based on scanning a QR code, is between Element Desktop and Element Mobile, but...
3. Element on iOS is absolutely awful. The worst interface I've ever seen. Extremely busy and convoluted. Rows of horizontally scrollable icons, duplicated as lists? Chat views where spacing is all off? It doesn't work for small group chats and doesn't work for large public chatrooms.
4. Element on iOS won't play GIFs. Element on Chrome/Electron only uploads the first frame of a pasted GIF. This was actually a deal breaker for my social circle.
Frankly, just compare the user experience of Keybase and Element. Keybase got it right.