It must have something to do with the new tensor chip (?), but performance on the pixel 6 series phones is very bad. Maxing out the settings on my old Galaxy note 8 from 2017 lets the game run okay, but doing the same on my pixel 6 allows for only a few frames per second.
After messing with each setting individually, it seems like the settings that have the biggest impact on performance are: ambient occlusion, LOD distance, and terrain texture quality.
Having everything else completely maxed out, with these three settings all the way down, performance is pretty good.