Pop!OS seems nice, but I never really got the impression that System76 is doing much more than just reskinning Ubuntu. It just doesn't feel like something that will last.
Going back upstream is an option of course, i.e., Debian. It seems to have modernized quite a bit since the olden days.
At least there are choices. :)
[1]: https://blog.system76.com/post/more-on-cosmic-de-to-kick-off...
FOr now it doesn't worry me much. Ubuntu is fine if you just remove the bad parts. If it becomes a problem, I see both Mint and Pop easily switching to Debian.
I think this undersells Pop!_OS a fair bit. They have a FAQ that actually has a heading "Isn’t it just a re-skinned Ubuntu?"[0]:
> To call it a re-skinned Ubuntu brushes over all of the features and quality-of-life improvements that Pop! developers work diligently to create. For an in-depth look at the effort and manpower that goes into updating and maintaining Pop!_OS, take a look at our Roadmap documentation and the This Week in Pop! series on Pop!_Planet. Below, you will find a general list of improvements that make Pop!_OS stand out.
I think roadmap doc they mention[1] tells the story pretty well.
[0]: https://support.system76.com/articles/difference-between-pop...