I dug up my old Lumia 950 Windows Phone the other day.
Now I'm sad.
I'd convinced myself that Android isn't that bad, really, but half a second of seeing smooth 60fps UI animation, a single reactive swipe of the home screen, and I am (once again) wondering why the world decided that windows phone, and webOS, and Blackberry 10 (aka QNX) had to die, and Android may live.
Update: I tried Sailfish 4.
They don't :(