AFAIK it's more or less still being worked on. Since Wayland has no support in the core protocol, it's an add-on which needs the compositor to forward input and output streams and then something to compress the video and forward it (+input events) further over the network. I can't say that I got it to work so far, though screen sharing in MS Teams(!) running in MS Edge for Linux does work and uses much of the same functionality. That is with KDE and kwin-wayland.
Anything not in the core protocol might as well not exist. It is literally, by design, impossible to write a fully featured desktop using the core protocols by themselves.
