It doesn't even look good. It doesn't even look "clean" or "sleek". It's just sterile. Dead. Non-functional.
I use Windows Blinds to make my Win10 look like Win98, and certainly I don't expect anyone to go that far, but some time between then and now, we've lost the plot.
I wonder why this is happening, and am constantly surprised at how readily the world seems to accept these changes. Perhaps I am getting old.
The change is only on the delimiter line between inactive tabs, and you still have space and each favicons between them, it's not like they all magically blended together. I actually didn't even realize the line disappeared until seeing this post.
All in all, new design can look good or bad, but this specific one has sensible trade-offs and functional advantages, which is to me far from just following a random trend.
It starts at Big Tech (Material Design for example). I think we should teach designers history of UX/UI and how things used to be. From 1950's typewriter UX to the latest AR tech. This education can put perspective and curate a better understanding of the user. A more empathetic approach. Not fashion trends, rounded corners and huge purple typography.
Big Tech operates like a horse-eyed A/B tests driven UX/UI machine and doesn't understand anything but. There is no Steve Jobs to overrule.
Here's a good example: Check out all of the small SUV's you see now, they're all elaborations on the same shape and form. I think this is by design, in that deviating from the norm right now is not something that is rewarded, but giving something visually 'safe' that hits most of the needs of their customer is acceptable.
[0] - https://cdn-images-1.medium.com/max/800/1*RCyvppE9R3x85bCAmn...
[1] - https://5thcolor.files.wordpress.com/2012/03/all-cars-look-a...
For instance I'd like to claim that Apple is an industry leader that has been misattributed as a design leader; it isn't their slick aluminum rectangles in isolation, it is them cohabiting with a marketing message and brand position working together that gave it the entire perception that leads to their success.
If say, Dolly Parton came out with a restaurant themed after a country jamboree and it went gangbusters it'd likely be incorrect to conclude Starbucks should have bales of hay and employees in 10 gallon hats and spurs to increase sales. A country themed restaurant is the correct way for Dolly Parton to execute a restaurant because she's Dolly Parton. It's not a brilliant idea in isolation and it's certainly not one that should elbow its way into other established brands in the same product category.
Yet this is the exact kind of logic that is done in software. We ignore the context of why something was successful for a particular institution and pretend it is transferable to all similar institutions regardless of context.
It's just not smart.
Of course, if it's just for fun then we shouldn't be asking why!