I don't mind it on my phone, but agreed that the Mac version just is not good. I've never understood the obsession with making sidebars translucent, and the new version made it much worse, and expanded that philosophy to the whole OS. I've been using it since betas (that was a mistake) and I don't like it any better.
Even stuff that uses a more "clear" material now is a bigger obstruction of the content below it than the old translucent gray versions were. The huge play/pause blob over videos looks like a transparent material, but you can't see a goddamn thing through it anymore because they turned it into a crazy lens. For all the talk of the new UI getting out of the way of content, it really is a big shiny attention grabbing blob that blocks your content. You can get a hint of what colors are underneath it, and it's shiny.
The trend in Apple's design for years feels like it's been making things look pretty in screenshots, but less functional and worse to use.
Another recent fuckup is the Apple Watch's redesign where they traded scrolling lists of cards for full screen slideshows, because you wouldn't want to see what's coming or what you've scrolled past. You used to have more than one item in view at a time, and it was a hell of a lot easier to stop scrolling at the exact right spot instead of blowing past the thing you wanted to get to.
Also bad, the System Preferences redesign. The rearrangement of that wouldn't be as bad if the search bar could reliably find and take me to all of the settings, but it can't.
If they put someone in charge who prioritizes usability again, I don't think this is much of a loss for Apple. Heck, maybe he'll bring his design priorities to Meta and help Apple make a comeback with whatever their smart glasses / AR play is.