That's simply not true.
Without NVIDIA Broadcast installed separately on my computer or any filters on my microphone source in OBS, there is significant noise suppression going on. Levels drop to zero when there is only audible computer fan noise, quiet speaking gets garbled if there's competing white noise.
My Blue Yeti sounds entirely different in Audacity than in OBS using default settings with each.
No filters enabled:
But here are my levels with the laptop fans on full blast: