High DPI on Linux is indeed a mess, but I find running the screen at a lower resolution preferable to Apple's implementation of DPI scaling anyway.

Bluetooth is very broken too. Not sure if that's an issue with the drivers or the Linux bluetooth stack in general. Fortunately I only use it for my wireless headphones, which I can live without.

WiFi used to be a big problem when I tried Linux on a Mac at a previous job, thanks to terrible Broadcom drivers, but that all seems fine now.

Been running Linux on a Mac for 2 and a half months now, for me personally the improvements are significant and the issues minor.