An honest list of Pixel OS features that don't work would be a great resource, and transparency makes everyone happy.
In addition to the ones listed above, I can think of...
Call Screen
Hold For Me
Shizuku*
Pattern unlock
Face-recognition unlock
Double-tap on back of phone**
Weather info on lock screen
Trusted Device unlock
Most QS tiles don't work from lockscreen
Select text via screenshot/Recent Apps view
Voice typing
Pixel Stand fast charging
Audio captioning
It's getting late and that's all I can think of for now
*and any app-based script execution. May also affect things like Termux and Tasker, although I don't use them enough to confirm
**The app TapTap replicates this feature