Good to see I'm not alone with this. I have multiple monitors with various resolutions (4K, 2K and an old 1600x1200 VGA screen) and I like the fractional scaling methods Wayland has. It makes it really easy to combine all of these screens into one useable area.
Fractional scaling on X11 can be enabled but it's such a massive performance hit, that it doesn't make any fun or sense to use it.
On my UHD 620, Wayland is rock-solid. Everything just works, it never crashes, I don't have any glitches and the performance is great. On Nvidia, when it's not just crashing it still feels laggy. Even moving around windows seem to be a struggle for the system and it's so sad to see that.
Hopefully this will improve in the near future.
I tried upgrading to the 550 beta driver now and it just segfaults in libnvidia-glcore.so when I try to run anything Wayland-related. Can't even get to sddm with it anymore and have to start KDE from a TTY. Of course, xorg still works fine.