This stuff is of course subjective, but a lot of the "improvements" on that page involve adding a bunch of extra whitespace everywhere, the exact trend a lot of people are complaining about nowadays. I'm not saying it's bad per se, but I would not present the design choices on that site as broadly good either.
It's fascinating, since I don't get the impression that UI elements needing room to "breathe" was an ironclad rule during for example the era of Windows 95. It sounds like folk wisdom for everyone on the same bandwagon of mobile-first. So much creative design potential (and admittedly some inaccessible ones) is lost when these opinions are passed down as the rule of law.
Another bugbear for me personally: rounded corners. Ask online and it feels like people just parrot the idea that rounding is "more friendly and pleasing" over and over, as if blind repetition of an ideal makes it true. But I've never looked at a picture of old webpages or UI frameworks with sharp corners from 20 years ago and go "that's unfriendly." It feels like with this one, a couple research papers came out a while back showing that rounding makes users spend less energy on element identification, and then used that outcome to conclude "well, I guess a huge swathe of UI design is now a solved problem."
Subjectivity died with the need to squeeze out every last drop of "efficiency" out of every UI design. And no, I don't think that rounded corners are friendlier and more pleasing than all alternatives. In fact, I believe they are a staple of the web and modern UI design in general homogenizing into a bland, unremarkable mess, and are thus irritating. I just border-radius: 0; everything globally and call it a day.
