My experience is that a high-end device like MixPre II is fine with a dynamic mic. Focusrite or Tascam US needs a cloudlifter to get enough (clean) gain. Random stuff like BlueYeti is hopeless with crackling noise.
So maybe you don't need a great ADC but you have to choose your audio interface very carefully (for its preamp.)
Typical interfaces have a fine ADC and some kind of pre, but the pre might be noisier than desired when paired with an unusually low-output microphone, so if you already have an ADC via motherboard line input then you "just" need a pre. I don't mean to lump all dynamic mics into this problematic low-output category (SM58 is much higher output than SM7B, both are dynamic) but we could certainly say that condenser mics should never be in this category when a few inches from someone's face.
Why are mics like the SM7b better than mics like the MV7 or elgato one that just work over usb? I don’t understand how they actually work or why all the extra equipment (audio interface, gain booster, cables) is worth it - what’s the tradeoff being made when you use USB?
Getting super high end with microphones is only really applicable in the music industry IMO.
Fun fact: Michael Jackson recorded the vocals for Thriller on an SM7B.
It's like asking what makes a VM better for a website when I could just use a SaaS site builder. Use whatever works; depending on your goals you might end up with the exact same finished product.