So if you choose not to do the thing that is designed to make the process simple then the process is exactly the same as it is for me on just about any other site/system when I log in on an untrusted device. I don't really see it as unnecessarily convoluted, but even if it was, you inflicted that on yourself did you not?

I care a lot about privacy and for me personally, logging in to discord on my own phone in order to log in on seamlessly on an untrusted device seems less bad than logging in to some arbitrary system using my actual creds. The latter combines any threat from discord with threats from password sniffing either while I'm getting creds to the device or on the device itself.