So my issues are with Element and not matrix specifically.
Dropping Element One was not a great decision. This was a great opportunity to get funding and let hobbyists in a the ground level without insane business pricing that reminds you of Microsoft or Atlassian.
The devs convinced the leadership to completely halt improvement of features and implementation of new features to rewrite their codebase in an obscure and niche language that offers minimal benefits. Yes Rust is cool. Yes rust may be more secure. Completely re-implementing your main client in a new language while removing tons of functionality was a bad decision.
There's no mobile client support for spaces, you can't browse public rooms from mobile, threads is horrifically broken, replies are terrible, they completely redesigned the emojis but dropped support for / commands.
Element Server Suite is terrible, it isn't even close to enterprise level. There's no meaningful way to manage rooms at an admin level. There's no way to manager users through MAS in a reasonable way. You can't let admins take over rooms unless there is an admin bot in every room, including DMs. There's no way to manage federation. Requiring K8S to run a chat server is insane. The entire stack is way too heavy and most of the features that would make it worthwhile are pure vaporware.