I don't care if anyone has a Xiaomi, Oneplus, Samsung, etc. Each brand is using a modified version of Android, and they chose to be compatible with each other. But for example the "blue vs green bubble" drama is a thing specifically because of Apple locking their unsuspecting users into a closed ecosystem. And it sure isn't Android's fault for not being compatible with it.
The more power a company like this gains, the worse will it be for the whole industry.
I also have a Fairphone 4, but I have encountered no significant bugs I can remember.
Installed LineageOS on it though, with microG, instead of /e/.
Can you tell me what issues you had?
My FP4 was affected by the "ghost touch" hardware bug, i ended up getting a replacement screen after contacting support. (it never fully went away, it has a few spasms every once in a while)
also the crashing while connected to 5G put me in a few pickles. sometimes when receiving a call while watching youtube the call's notification bubble will take up to 5 seconds to appear at all.
it seems to also ocasionally forget that it has a SIM card installed, though that sim has been in use for 10+ years, so i can't say if that's the Fairphones's fault.