Make appearance (dark and light mode) A drop down box like Windows 11 settings.
Evidence or User Insights Windows app have the trend of keeping the radio button while other use the dropdown box. The drop down box makes more sense in my option as it's consistent with Windows 11 and quicker to access/see what selected.
Proposal Make it a drop down box following Windows 11 "chose your mode" style
Low-Fidelity Concept

Requested Assignment I'm just suggesting this idea. I don't want to implement it.
This is your friendly Microsoft Issue Bot. I've seen this issue come in and have gone to tell a human about it.
Other Microsoft UWP software does not have that layout. Appearance settings The layout is unified with the current layout. Also, the Files app has the layout you suggested.
Personally, I prefer the current layout.