Plants, depending on the year, are really hard to identify even with a trained eye. If an AI algorithm is training on, say, only the blooming season versions of a plant, then it will do a poor job of identifying the plant in the Fall. Same for human submissions, usually they are photographed when they are in bloom.

I teach an environmental science course and we have a lab where I have students use iNaturalist for plant identification but the Fall semester students are always at a disadvantage, we have to crack open the dying plants for identification.