Because I have this Android phone sitting on my desk for development. When I bought it it was almost as responsive as iPhones (and much cheaper). 4 years later the UI is a lagfest [1].
Meanwhile, my iPhone XS is over 5 years old and almost as responsive as on day one. And I have major version OS updates to blame for the "almost", while the Android one got one major update and was lagfest even before that.
[1] I don't even use it every day, Android development is kind of a side job once in a while.