My hypothesis is today's "modern" OS user interfaces are objectively worse from a usability perspective, obfuscating key functionality behind layers of confusing menus.
It reminds me of these "OS popularity since the 70s" time lapse views:
https://youtube.com/watch?v=cTKhqtll5cQ
The dominance of Windows is crazy, even today, Mac desktops and laptops are comparatively niche
Eventually, I stopped using it because: 1- it was always annoying to send an screenshot to someone and have to explain that no, I wasn't using Windows 95, and why; 2- the grey-ish look of everything started to bother me over time; 3- I wanted a more integrated desktop experience and moved to KDE Plasma. Still, I configured my Plasma to work like old Windows: window titles on taskbar, zero to none animations, etc.
I think this started with Vista, I remember watching a video criticizing the new love of glass effects on UI chrome as it got rid of or minimized the color/shading difference between focused/unfocused windows. The example the video used was 6 notepad windows and pick which one was focused, and the main cue you'd need to look for is that the window with focus had a close button colored red.
Thin borders and minimalist/hiding scrollbars is another one that annoys me, give me something graphical for my gaze to grasp.