Magnitus: People obsess about changes in the GUI (which have not been revolutionary btw), because there is nothing else to talk about.
To be fair, it's not just Windows. The most exciting thing about newer versions of Ubuntu for me (and you could substitute any Linux distro in that statement) are what the more cutting-edge system software I use (containers and the like) might be able to do achieve with the new kernel features and greater hardware compatibility (it's more flagrant in Linux, because hardware folks cater to it less out of the box so newer more mature drivers will make a big difference there).
However, most of that stuff is nothing to get excited about for the average user. Windows makes a big deal of out of (a lot more than Ubuntu), because it's big money for them and they got to convince people to shell out the cash.
The most exciting innovations at this point happen at the application (and occasionally system software) level. The glory days of OSes have waned. They may yet come out with something truly exciting, but imho, they haven't done so for the past 10-20 years. It's mostly been about refining the existing formulas and that yields ever diminishing returns over time.
Saying that nothing interesting happens on OS-level is a gross misconception. Probably explained by the fact that 99% of the users never directly interact with the kernel(aka "the OS").
But guess who makes neat stuff like containers possible ? The system software just uses the virtualisation support that was implemented at OS-level. And maybe the the average user won't care about containers. But stuff like flatpak will likely bring a "cool new thing" for him, and that uses the same features under the hood.
Same way things like GPU-accelerated video decoding are only possible because it is implemented at OS-level + providing a nice interface to make it usable for user application. Efficient and fluid video playback on youtube is not a feature brought to you by your browser :p
Or just think of the whole area of energy management / energy efficiency. Dynamically scaling CPU/GPU frequency, switching off unused hardware parts, etc.All that stuff started pouring into OS design/programming like maybe 10-15(?) years ago and brought a fundamental change compared to how things were done back in the early days.
Without this work happening in the OS, mobile computing as we are used to it today would have been impossible.
If people talk only about visually changes that is often simply due to ignorance or lack of interest.
I mean, let's be honest, for the majority of users the inner workings of a computer is like magic.
All that matters is the stuff that you see on the screen.