Neither. Screensharing was a massive issue for a while, but it's now far easier than X11 because the server/portal is responsible for a lot of the more fiddly bits.
The underlying problem is that the protocol (ABI, really) has to be specified and implemented for these things to work. Screensharing was a prominent early example of something which hadn't been through that process. It was a very visible issue, an easy wound for hardcore X11 fanatics to pull at, and - apparently - continue to bash on long after it has been solved.
Clipboard woes have likewise been solved.
Mouse and keyboard injection has not yet been solved, but I recall there being some draft spec to that effect.
Ultimately, if Wayland does 100% of what you need, you should be using it because it generally does those things better. If it doesn't do what you need, then stick with X11 until it does (and support for that protocol is widespread).
The underlying problem is that the protocol (ABI, really) has to be specified and implemented for these things to work. Screensharing was a prominent early example of something which hadn't been through that process. It was a very visible issue, an easy wound for hardcore X11 fanatics to pull at, and - apparently - continue to bash on long after it has been solved.
Clipboard woes have likewise been solved.
Mouse and keyboard injection has not yet been solved, but I recall there being some draft spec to that effect.
Ultimately, if Wayland does 100% of what you need, you should be using it because it generally does those things better. If it doesn't do what you need, then stick with X11 until it does (and support for that protocol is widespread).