The attack vector that DoH offers is that data exfiltration companies will start shipping their own DNS resolver in javascript to work around DNS-based filtering. They can't do this with regular DNS because the network traffic can still be observed and blocked independently, but how will you block a browser from accessing specific https URLs without MITM'ing all traffic?

So yes, DoH does have something to do with DNS choice: it can completely subvert the OS-provided domain resolver service as well as the browser-configured one.