That was my first thought. All this crap Mac users have to go through if they want to go off the "happy path" even slightly with an aftermarket monitor.
I worked for Apple more than two decades ago, but now I'm a happy Windows 11 user.
I have an aftermarket monitor, runs at 4K, has a scaling factor applied so that I can make everything bigger. I don't feel like I had to go through any crap, either, it's the simplest of UIs.
I agree that it is simple (i.e., the Displays pane of System Preferences) but the result IMHO is unpleasantly blurry.
These days, fonts, SVG images, CSS, etc, are stored as mathematical descriptions of curves that can be rendered at any scaling factor. Any use of a scaling algorithm, like MacOS does when the scaling factor is not an integer multiple of the display's true resolution, is an unnecessary source of blurriness. A HiDPI display make the blurriness less noticeable, but do not solve the basic problem, which is that the scaling algorithm reduces the "effective resolution" of the display.
(I have never used a HiDPI display with a desktop OS, but another participant here on HN has and reported that he notices MacOS's blurriness relative to Windows even on a HiDPI display.)
I worked for Apple more than two decades ago, but now I'm a happy Windows 11 user.