Basically the title, I want to use my laptop, which uses Arch Linux, and my tablet, which is an android one, as an external monitor for my desktop pc.
Quite sad actually, that you can’t just use laptop displays as external displays.
I believe you can buy a dummy HDMI plug and use Deskreen to host the screen in a webserver. This should work, but I don’t think it’s a good solution.
Edit: Deskreen seems to no longer be maintained and therefore doesn’t support wayland. I think it’s because of the Ukrainian war, and the creator being directly affected by it.
I did that from scratch a long while ago by creating a virtual x11 screen and vnc-ing to it from the tablet.
On some GPUs it works without a dummy plug.
There are some instructions out there, but I can’t search them (or my scripts) for you right now, sorry.
If you can’t manage to make it work, ping me again in a couple of days.