Once this is deployed, Matrix will finally be providing the bare minimum to be actually workable. About time.
Then we can finally try and bring in everybody who's currently trapped in proprietary IM.
Most of the problems lie in the clients though. Which should improve with element X.
AIUI Element X is just an element build with these "Matrix 2.0" features. It is not a new client.
Both the servers and the clients will have to be updated to leverage them.
Element X is an entirely new client written in Rust + Swift UI/Jetpack Compose (https://github.com/vector-im/element-x-ios and https://github.com/vector-im/element-x-android) which will eventually replace the legacy Element apps (https://github.com/vector-im/element-ios and https://github.com/vector-im/element-android).
The features already exist serverside; we're just working on getting them out of beta.