There are some desktop and environment changes, but Pop also have a really good power management module that no other distro has, and good compatibility aroung different GPUs combination, and that is a big deal in laptops.

I had some problem in the past with a laptop with Intel GPU + AMD GPU interchangeable graphics in other distros while with Pop is ready to use after installing. AFAIK, those who had Nvidia Optimus and similar Nvidia technologies had a lot more of troubles outside Pop.

I haven't used Ubuntu in ages, so I don't know how those things are actually managed. Probably they aren't far behind.

Anecdotal evidence, I know... But there were several things that just didn't work right for me on vanilla Ubuntu that Pop made right when I switched 3 years ago. Mostly graphics related in my case.

I think it's important to remember that System 76 has been "making Linux work on hardware" for over a decade now, which is a totally different mindset to building a distro than most maintainers have.