I attribute System Preference's failure to be not creating additional icons and groupings that were properly descriptive and respectful of user use - for example: Gatekeeper should have been its own icon, not buried inside of Privacy and Security, then under a separate tab. From my experience, it was the primary feature to access within preferences. Further, yes, many improvements should have been made to Preferences, no doubt - Settings doesn't seem it though.

Settings doesn't make sense because the sidebar assumes a 'full screen / most of screen at golden aspect ratios' paradigm for the active window - which is absolutely not true for System Settings on Mac. More clearly: the sidebar works well when your mind can 'group' the edge of the bar, with the edge of the device. This works wonderfully for iPad - your mind can 'section off' without much mental effort. It's how excel usually works too - what madman would use excel at the aspect ratio of System Settings?

You now have a vertical and horizontal visual plane to mentally track - that also doesn't align in it's own window (what is Search, AppleID Profile Pic, etc doing anchoring the layout at top left) - and now all the controls are basically outlined table cells with weird choices for the controls. Try going to Desktop & Dock and identify what exactly are the groupings for the tables for 'Dock'? now I have to figure that out, too?