Outside of your fantasies high DPI works fine. Modern QT apps seem to pick it up fairly automatically now and GTK does indeed require a variable which could trivially be set for the user.

Your desktop relies on a wide variety of env variables to function correctly which doesn't bother you because they are set for you. This has literally worked fine for me for years. I have no idea what you think you are talking about. Wayland doesn't work AT ALL for me out of the box without ensuring some variables are set because my distro doesn't do that for me this doesn't mean Wayland is broken.

This wasn't true in 2003 when I started using Linux in fact the feature is so old I'm not sure exactly when it was implemented. You have always been able to have different resolutions and in fact different scaling factors. It works like this

You scale your lower DPI display or displays UP to match your highest DPI and let X scale down to the physical size. HIGHER / LOWER = SCALE FACTOR. So with 2 27" monitors where one is 4k and the other is 1080p the factor is 2, a 27" 4K with a 24" 1080p is roughly 1.75.

Configured like so everything is sharp and UI elements are the same size on every screen. If your monitors are vertically aligned you could put a window between monitors and see the damn characters lined up correctly.

If you use the soooo unfriendly Nvidia GPU you can actually configure this in its GUI for configuring your monitors. If not you can set with xrandr the argument is --scale shockingly enough

Different refresh rates also of course work but you ARE limited to the lower refresh rate. This is about the only meaningful limitation.

It's painful because the developers took 14 years to produce something semi usable while ignoring incredibly common use cases and features for approximately the first 10 -12 years of development

Most people have more thinks to do than fix things that already work.

You actually feel like killing chickens and killing people have equal moral weight? Ya you aren't worth talking with any longer.

I just passed scale to xrandr after computing the proper scale and then used the nvidia-settings gui to write current configuration to xorg.conf its not incredibly hard basically all you are doing is scaling lower DPI items up to the same resolution as your highest dpi item and letting it scale down the correct physical size. For instance if you have 27' monitors that are 4K and 1080p you just scale the 1080 ones by 2 if you have a 4k 27 and a 1080 24" its closer to 1.75. The correct ratio can be found with your favorite calculator app.

You can set this scaling directly in nvidia-settings come to think of it where you set viewport in and viewport out.

"A little blurred" You are probably one of the fellows who walks around with a phone with a spider web of cracks because it "still works". Not sure why you imagine a blurry screen is a usable or acceptable thing. Excuse me while I return to using my 4k + 4k + 1080p 3 screen arrangement in which NONE of them are blurry and in which an app that is moved from a->b remains the same size because UI elements are scaled to the same identical size.

rerequisites

wayland, including wayland-scanner and the base protocols
libxkbcommon
libtls (either from libressl, or libretls)
A compositor making use of wlroots, or (on an experimental basis) KDE, or (if all else fails) the willingness to run questionable networking utilities with the privileges to access /dev/uinput
wl-clipboard for clipboard support (only works on wlroots, not KDE/GNOME)

...

In my case, a 'uinput' group is created, and a udev rule is used to modify the permissions appropriately:

/etc/udev/rules.d/49-input.rules, in my case

KERNEL=="uinput",GROUP:="uinput",MODE:="0660"

From here, one could assign one's users to this group, but doing so would open up uinput to every program, with all the potential issues noted in the first paragraph. The safest approach is probably setgid:

as root -- adjust path as needed

chown :uinput waynergy chmod g+s waynergy

If this doesn't still doesn't seem to work (as in #38) be sure that the uinput module is loaded properly. This might be done by creating a file /etc/modules-load.d/uinput.conf with the contents of uinput

This is compared to just installing synergy which takes 7 seconds. I'm not sure why anyone imagines this is a credible alternative.

The author is a Wayland fanboy which almost by definition makes them a moron. We are talking about folks who were singing the same song like 7 years ago when the crack they were promoting was outrageously broken for most use cases.

Multiple displays work fine. The only thing that needs to be drawn in the root window is attractive backgrounds sized to your displays I'm not sure why you think that is hacky or complicated.

This is literally the exact bad attitude of your average Wayland proponent. The thing which has worked for 20 years doesn't work you just hallucinated it along with all the show stopper bugs you encountered when you tried to switch to Wayland.

This already works on X and indeed has worked longer than Wayland has existed.