Earlier quoted context omitted.
Except the author is using X11 as many people will. And what this shows is how many different environments / toolkits / settings there are out there. It would be nice if distributions would do a better job of handling this for you. I’ve run into the same issues myself, and it’s kind of hard to believe that I even had to figure out these configuration dpi settings in 2021.
The point is, you don't have to figure out configuration dpi settings in 2021, if you use distributions as they are supposed to be used . If you insist on your favorite x11 window manager, the integration is on you. No point in complaining then, it is self-inflicted pain.
As much as i like the concept of Wayland, until it's a one click always works without any caveats option in Ubuntu it essentially doesn't exist. Ubuntu 20.04, the latest of the most popular distributions, does not have wayland enabled by default. They actively discourages you from trying it if you have Nvidia, which again is the most popular gfx card - not sure if one is supposed skip the proprietary drivers or not with Wayland but on X11 using Nouveau is not a pleasant experience.