at its utmost extreme it just becomes impossible to identify the species without genetics (even if things are not heavily split) and we just end up having a parallel taxonomy for use by anyone who doesn’t have constant access to a genetic sequencer. Cryptic species exist that are genetically distinct, but in terms of ecosystem management and nature study by anyone other than geneticists, it’s just not even accessible to us unless we get to the point of star trek style ‘trichorders’ that scan genes of any organism we get near.