There are definitely relevant subspecies in zoology; some species look quite different in other parts of their range and they deserve their own category (although I expect most of the obvious examples of these will eventually be split into their own species…). But at least with North American birds I get the impression there was an excessive amount of new subspecies being described at some point in time and no one has cared enough to clean them up. eBird often lumps them into more identifiable informal “subspecies groups” which iNat doesn’t support currently.
The only plant subspecies I know is European Reed (Phragmites australis australis) which makes sense to me compared to the American subspecies. But sedges, asters, sowthistles etc. are hard enough to ID to species that it confuses me when someone randomly decides to take one to subspecies…