Apple software isn't bad, but it is often obtuse and buggy. And, with iOS 26, usability has taken a big hit.
On macOS when I connect or disconnect an external monitor, my applications get all confused on where they should display, especially if I then reconnect a monitor. On KDE when I unplug my monitor everything goes nicely onto one desktop. When I put a monitor back in, everything goes back to where it was before. It just works.
On macOS, every time I install a new program I need to do some dance with System preferences to allow it to run. I tried some command line settings that supposedly disables this, but it never sticks. Every few months, the process is different than it was before. On KDE, I just run my software and it works.
On macOS, I don't have useful window snapping behavior or full-screen behavior, nor am I able to have focus follow my mouse. On KDE, I have these.
macOS just doesn't work for me. But the competitors have a good solution.
Computing should be personal. Some people like to mold their tools to their way of working. Others adapt their way of working to their tools. KDE is for the former, and macOS is for the latter.
Why would someone else use my criteria? They should use their own criteria? I certainly am not going to use your "it's niche so it can't be useful" criteria as it's important to my usage.
I'd need another hand to fully count all the Apple apps that have burned me in the past.