[harha]

I don't think having a similar UI as mobile is very good for the user since the input mode is very different.

I think macOS does way better here with a minimal use of white space because I can easily have a browser open on the side to look up what I'm trying to change - though some things do appear a bit old school (e.g. networking).

[whereistimbo]

The Settings app in Windows works very well with mouse and the wasted whitespace only appears when it's maximized, the app was made to be responsive with several windows sizes.

[Alopis]

Seems like you've never used it with a non-FHD screen. Or as a window. Because it absolutely wastes a ton of space. The sidebar on the right will disappear to the bottom, which is unnecessarily cut off because of the crazy large margins around everything. I don't understand why every page needs to be scrolled when the Control panel fit twice as much functionality into half or even a quarter of the space.