The low contrast material design makes it incredibly difficult to navigate, you constantly have to guess what is a button and what is not.
I think something like Windows 95 is peak interface design. Sounds facetious but think about it: Controls are clearly distinguished from content with not only colors but bevels. Buttons often have both icons and text so you don't have to guess what the button does. Overall it leverages real world spatial metaphors extremely effectively to produce an interface that is very intuitive. You never have to ask yourself whether a button is a dialogue or an input field because they look visually distinct.
For example Typeform, ruined completely because of this. Dropbox, completely ruined to please their 50 design team. iOS 7, completely ruined with a silly flat style who was perfectly addressed in Android with Material Design. Same with Windows, they wanted to go translucent because Mac OS X did it properly. They made the worst one.
Every single trend like this must be serioulsy explored, and implemented once that exploration is well poured. But on final products, just to satisfy that feeling of freshness or innovation, nah, better not do that.
https://dl.acm.org/doi/fullHtml/10.1145/238386.238611
https://news.ycombinator.com/item?id=12330899
I believe that the limitations of common consumer hardware of the time also helped. Designing around 640x480x4 basically forces designers to focus on function over form. Whereas today, one could get so lost in trying to make an interface beautiful, that they forget it's ultimately a tool.
I kinda miss skeuomorphism, one of my first websites was a blackboard with a chalk font I made for my high school in 2009.