> The problem is as soon as you run something new and it doesn't scale properly in X11...

QT, GTK, FLTK, and friends handle scaling correctly. Perhaps in the future there will be a Wayland-only GUI library, but I'm not sure why anyone would bother when there exist Wayland backends for the major existing ones.

> Pipewire

I don't use it. I use JACK2 with a PulseAudio fallback for Steam games and other programs that don't know how to hook into JACK.

> - No screen tearing by default

If you're using an AMD graphics card, the TearFree option gives you this. If your distro hasn't enabled it by default, then it's two minutes work, and work that I did years ago.

> - Per-monitor refresh rates

  $ xrandr | grep -A2 DisplayPort
  DisplayPort-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 698mm x 393mm
     3840x2160     60.00 +  60.00    50.00    59.94    30.00*
     2560x1600     59.94  
  --
  DisplayPort-1 connected 1200x1920+3840+0 left (normal left inverted right x axis y axis) 546mm x 352mm
     1920x1200     59.95*+
     1920x1080     60.00    50.00    59.94    59.99
  --
  DisplayPort-2 disconnected (normal left inverted right x axis y axis)
  HDMI-A-0 disconnected (normal left inverted right x axis y axis)
     

The rest of your concluding list is just as poorly-informed.