I don’t believe this is entirely accurate. My understanding was that IDs on an observation do help filter at least to kingdom, though perhaps not lower. For example, if you put the a photo up with a flower ID, the CV gives mostly flower recommendations, but if you put the same photo up and have a leafminer ID, the CV gives mostly insect recommendations.
This thread had more details about this behavior: https://forum.inaturalist.org/t/leafminers-have-broken-the-cv/54378/2, including a note from Tony that apparently this behavior doesn’t happen on all types of iNat.