jstewart You are welcome, and in the time since I originally wrote this, I have made more observations. One in particular is, I really do find X11 (x.org) somehow easier to look at than Wayland. So, that's one of the things I appreciate about the Steam Deck I have, that the desktop mode is using X11 for now (I don't bother using Linux on the PC I am writing this on because I was never really able to get it to Windows levels of satisfaction even with MX, in huge part due to driver issues). This extends to gaming on the deck, on my monitor I prefer looking at the games in X11 mode not Wayland. Probably MX defaulted to X11.
KDE supports fractional scaling in X11, so you could continue experimenting with that combo. Gnome does not support fractional scaling, only integer, so if you need to do 1.25 or 1.5 etc, you need to use KDE. Not sure entirely what method Xfce is using for fractional, but Gnome is trash if you need fractional as it is integer only so avoid Gnome if you need scaling. For those who don't know, how scaling is done will affect how clear or blurry text is.
Most of the examples you listed jstewart are using Wayland by default, so that might be playing a role in terms of the "feel" of the display.
Drivers are an interesting subject.. there's the kernel modesetting driver which almost everyone is setting by default now, and probably where all development goes now. But there is also (depending on the system) proprietary drivers. Intel has their own older ones for x.org which they no longer seem to be updating anymore, but they do feel different. I know Nvidia has a bunch of driver options (at least 3) and no doubt all of them feel different as well.