The thing is, there's "iwd" and "wpa_supplicant". You use either one or the other, but not both. Sources like the Gentoo handbook will tell you that but, not all Wiki's do as good a job of pointing that out <...looking directly at you Arch...>.
I don't understand anything to do with network configuration, I just install a few packages (iwd and wpa_supplicant included), start a few services, run a few commands, and hope it magically works after rebooting