Is hard to rate UI/UX of Android as a whole this days. In the last few years, each big manufacturer has created their own design language on top of stock Android and evolved in its own way.

- Samsung's One UI https://www.samsung.com/us/apps/one-ui/

- Xiaomi's MIUI https://global.miui.com/en

- OnePlus's OxygenOS https://www.oneplus.com/uk/oxygenos

- (Stock) Google's Material Design/You https://material.io/design

Yes, new Android versions bring new features for all of them. Many took ideas from Google's vision, and small manufacturers just use stock with a few tweaks. Also Google for his Pixels does exclusive stuff that do not goes to the Stock Android that every manufacturer can use as a base.

The point that I'm trying to make is that today is not much accurate to talk about "The Android Experience" (usually to compare it to iOS).