The Fundamental Problems with cross-platform frameworks
Juhani Lehtimäki

I agree mostly. But I think you underestimating Flutter. What I’ve seen is really hard to achieve with native and it goes beyond the typical demo cases.
MotionLayout bring Android back in the game but before writing animations with Flutters was far ahead of Android native. 
Also, Materialwise Flutter is doing better than Android itself which is hilarious, so there the typical rule that cross-platform is behind, does not really hold