>This leads to overemphasis on the visual aspect ....

For Apple, and specific to Apple, when they fired Scott Forstall, there is no one to protect the software UI guys. The 2012 reshuffle in the name of "collaboration" by Tim Cook saw Design team taking over everything design, including Software. 2013 saw iOS 7 and then they spend 3 years to walk back a lot of iOS 7 UI changes. In 2016 many of their old UI leads "retired". Having no old guards to defend their turf, giving Alan Dye more rooms for power grab.

Since then, if not earlier, despite the whole UI becoming more android and cluster mess, there have been little to zero major UI changes other than new skin.

And like Apple's software, that is 10 years of resume driven development where they just want to ship features after features.