Material design feels like it was designed entirely to look good with zero regard for usability. It uses way too much padding for everything and wasted tons of screen real estate.
On desktop, I found it to have weird buttons, weird spacing, weird controls and layouts with hamburger menus all over the place.
In terms of UI, Android 11 was the last good Android. Anything with Material looks awful. In fact, I will likely switch to Linux or Sailfish OS if possible when I have to replace my Android 11 phone.
I'm also not a fan of Material You to be honest, the "colors from your background" gimmick just results in all the colours being muddy boring desaturated ones, and the general low contrast + rounded look just doesn't work for me.
Even on mobile it's easy to miss! Google makes it a white button with a thin gray shadow, usually against white rows separated by thin gray lines.
If you squint, it literally becomes invisible because its visible weight is identical to its surroundings.
IIRC it used to be the solid accent color with white text, so you couldn't miss it. But now it's almost invisible unless you know where to look for it. It really is baffling.
Flat design has been the attempt to try to create a unified design language across desktop and mobile, since most people are constantly switching between the two and using the same apps across both.
You’ll be amazed how clean yet unusable the flat design is when you turn it off after a week