Though I have to admit, I did like the Holo aesthetic more. And I do miss affordances in UIs, and non-flat UIs, in general.
Material UIs are not perfectly flat; there is usually a shadow, so I can tell an element is distinct from the layer below it. The problem for me is that it often feels about as organized as the mind of a kindergartener.
Consistency of look-and-feel is important, but consistency of organization is even more important. How confusing would GUIs in the 90s have been without the File and Edit menus?
That's fair.
Unlabeled hamburger menu buttons and gear icons placed every which area (sometimes multiple!) are great examples of (admittedly common!) abuse of what can be a powerful UI concept.
I gave an Android tablet to a 90-something year old. She got on ok but there were a few frustrations. Stuff would close when it shouldn’t, button here just hard to reason about or get to etc. She asked if it was an iPad, obviously some brand awareness there. Switched to iPad as a bit of a fun surprise, and most issues went away. More stuff was where she thought it would be. (She has a feature phone from 14 years ago so it’s not iPhone preference.) She just turned 101 and you can’t take her iPad away from her. Loves it.
We can all get used to whatever. Try it on the edge cases and your opinion might shift because that’s where the differences emerge.
I’m holding back a lot of iOS rants here :) Selecting a single word is often many clicks. I’d love to be able to forget individual words that it insists on autocompleting to.