Enabling in X works via:
xinput list # find second mouse id
xinput create-master second
xinput reattach <mouse-id> "second pointer"
and to get rid of it: xinput reattach <mouse-id> 'Virtual core pointer'
xinput remove-master 'second pointer'
Works great for clicking, but keyboard doesn't work in some applications when enabled. Dragging windows might attach them to the wrong cursor and other issues. Playing around with xinput can also crash some apps (libgdk-3 here) or leave you in a state without a keyboard or mouse.The fact you're griping about implementation details like pipewire makes me think you also tried micromanaging your env and broke something. If you use a fresh install and leave everything default, I'm sure it would work for you like it does for everyone else. I use KDE too btw.
All the "micromanaging" you need to do to not have screensharing is one of the following; 1. Don't have a started dbus session 2. Don't have portals installed and setup 3. Don't have pipewire installed and setup
Meanwhile on X what you need is: 1. Have X
So no, it wouldn't work, the reason why it works for those people in the Reddit post is because they use distros and sessions that do all the things I listed that make screensharing not work if any one is not done.
PS: Wayland does have testing protocols for screenshots and screenrecording like 'wlr-screencopy' and some DMA buff one I forgot the name of. But for screen sharing there's nothing that Wayland implements itself afaik.
Or, did you remove some core OS services, and now you're complaining when various things started to break?
PERSONAL Computer