I think there will probably more users in the near future. The more AI gets intrusive, the more people will look for alternatives, and GrapheneOS is by far the most elegant solution -you get rid of AI, but still can use the apps you like and do all the things you did before.
I also think that Graphene is doing an absolute amazing job when it comes about installing the OS to a Pixel. The web installer is almost fool proof i would say, the only reason why it can fail is the USB cable or the rare case that someone has trouble with unlocking the phone.
Also to revert back to Stock Android is super easy and is a great offer for people who want to try out the OS.
The UI is fantastic in my opinion, I don't need fancy animations and super tiny fonts -i prefer a non spectacular UI without distractions.
What I would like to see is improvement for people with disability. iOS is much better in this than Android, it begins with font size system wide. Android can't do this yet, when you set bigger fonts it often destroys the look and usability of apps or web pages, iOS handles this much better.
But overall, I am very happy with this totally free alternative to Stock Android.
I use graphene for almost a year now, as a daily driver and my only used smartphone. It's super stable so far, bugs are almost not existing or if, they are mostly part of the ASOP Android and not a result of bad Software.
I remember that within the first month i was undecided if I shouldn't switch back to Stock, but it you take your time very soon it gets more and more difficult to switch back to Stock, because once you figured out how the things in GrapheneOS work, you don't want to go back anymore.
I tried some alternative OS in the past decades, but Graphene OS was the only one I would consider on the same level of usability as iOS/stock Android.