I’m not surprised to find dandelions being the subject of discussion again, haha! Yes, those are tricky, and so are a lot of other plants where there are multiple species that look very similar (e.g. Erythronium umbilicatum in my area and E. americanum).
Based on my own experience, in cases like this where there are fairly recent splits and field guides commonly only list one species and ignore the existence of the others there will be lots of errors in the IDs due to lack of knowledge/awareness. When I first started out, I was blissfully unaware of the existence of E. umbilicatum and consequently ID’ing all trout lilies I photographed as E. americanum. I have since learned there are two species that are difficult to tell apart unless some specific details are visible, and based on range maps all the ones in my area should be E. umbilicatum instead. I now know which details to photograph to clarify ID whenever I see them, but a lot of other people are still at the “blissfully unaware” stage of this learning curve and a lot of iNat observations consequently are missing the details needed to clearly identify the species based on morphology.
Errors may be present even in herbarium records (see the note here: https://auth1.dpr.ncparks.gov/flora/species_account.php?id=3458), though those can often be corrected by reexamining the physical specimens. Certainly a researcher working with these would have to take extra care to confirm everything. I doubt it will ever get sorted out on iNat level.