Android actually does have a desktop mode when you connect an external display. I'm not sure how much this is standardized / merged into AOSP, but I use it with my stock Pixel 10 Pro.

I would describe the experience as... passable. Historically it was quite glitchy but recent OS updates have improved it. The biggest issues resolve around apps which do not scale their UIs correctly.

It is a stock part of Android. You can plug your Android phone into an external display and you'll get an experience like the Googlebook.