you can make a USB mic sound good. there's this magical thing called VSTs and there's a bunch of them available for free.
my favorite suite has to be this (account required):
these are more geared towards music production but some plugins in this suite can be used to improve your mic quality.
keep in mind that OBS only officially supports VST2 (as of september 2023, before the stable release of v30). however, there are plugins for OBS that add VST3 support (shoutout github).