I have the official Apple Lightning-Aux for my AKG K361 and Grado SR60x. It has definitely adequate audio, no complaints.
I use the Apple USB C-Aux I use for when I use any headphones with my gaming PC (usually Koss Portapros). Also definitely adequate.
My impression with either one is - except for physical durability concerns, if either adapter can power what you’re plugging into it they’re awesome. If you need more power or physical controls or weird connection formats that’s where they start to not be great.