Didn't uninstall any of my AdBlock layers, but YouTube didn't survive.
Even though I actually never saw the famous popup, the whole thing made me take steps after months of feeling that the recommendations sucked and I was often wasting lots of time watching stuff I didn't even like.
Now I'm actually getting back into reading and audiobooks, and using invidious for the occasional watch.
I wouldn't use a complete macos theme with the logo and everything, but the mac design language does have some pretty nice details that even help usability.
For example, I love the double outline that macos windows have, the normal darker line and another lighter inside. To me, it really separates windows when I am working with several, and they overlap (I use mac at work), in addition to looking nice and giving some depth. That's just a little detail, but there are many like that one that is easy to see why someone could appreciate them.
Obviously it varies from person to person, there's also stuff that I don't like, but I do can see why someone would use a theme like that.