The only app I use that doesn't have a problem is Alacritty, which is the terminal emulator I kind of have to use to avoid this problem. Other terminal emulators I've tried do have this problem.
For the other examples it's probably XWayland scaling at 1x and then being scaled up instead of 2x and down. The patches to fix that exist but I'm not sure where they're already merged in. All those apps except Emacs should go Wayland native in the next few months though.
Sure, eventually, that will be the case.
But right now, most GTK apps are not Wayland native and look bad on Wayland. Those that are Wayland native have so many bugs on Wayland that they are still objectively significantly worse than their Xorg alternatives.