* The community is unnecessarily toxic from what I've seen: there's a lot of following dogma without asking "why". It leads to this very insular userbase that often turns outwardly toxic towards other projects, which is an issue that goes forever unfixed (ie. This post on the F-Droid forums originally was far more aggressive towards the F-Droid project before moderators edited it to be less aggressive: https://forum.f-droid.org/t/google-will-require-developer-ve... ). Other, older places I've seen this come "from the top" include hostile relicensing of Vanadium's patches to prevent other Chromium forks from making use of them.
* Instead of blockading SafetyNet as being a user hostile solution, GOS instead... implements their own version of it. Which is hard to see as anything other than basically recreating the same walled garden you get on stock Android.
* Pixel exclusivity is dumb and remains dumb. Pixels are very mediocre devices from a usability angle; they're large, have pretty inefficient battery life and in my experience are prone to becoming hot very easily. (I also managed to randomly brick one during a routine stock system upgrade, so there's that; not on GOS obviously, just noting that the Google side of the flagship Android is pretty lackluster too.) There's also a forever hypocrisy in defeating Google spying... by giving more money to Google. The motives for this seem to mostly be tied to a promise about the Pixel's security chip being open sourced eventually, but this is a forever promise Google isn't willing to cash out on. GOS has a token line on their site saying that most patches can be used on other OSes with little effort, but there's zero effort from any community to actually make these. (The reason for this can be blamed squarely on point 1; there's an insanely hostile reaction to anyone trying to do a fork for this sort of thing, which is basically enabled by the lead devs because of what they did w/ the Vanadium license.)
* Finally, GOS doesn't let you do hosts based adblocking, instead encouraging you to use the Android VPN service instead. A simple solution... that isn't really realistic because the Android VPN service only covers running one VPN at a time, meaning you have to pick between adblocking and privacy/accessing your own internal network.
Finally, a broader problem is that from what I can tell, GOS as a project doesn't quite grasp the relationship between app developer and app user and how it's become toxified over the years. Things like their ongoing signing beef with the F-Droid project (an incredibly niche issue that doesn't matter for most users) suggest to me that GOS is at best extremely naive/unrealistic on the issues that affect app usage for the common user. The problem these days is usually the developer going bad, not a third party.