That pretty much sums it up, there's a reason all of those custom ROMs pivoted to supporting basically just Pixels. Apart from Pixels, your only options are Fairphone and a few years old Chinese models (Xiaomi, Motorola, OnePlus), none of which are even close to state-of-the-art hardware.
Custom ROMs are pretty much dead, this just might be the final nail in their coffin.
Well, Pixel is arguably pretty shitty hardware as well