I think @choess’ comment was in the context of land plants, perhaps even more specifically, vascular plants, even flowering plants.
But yes, fungi are certainly in an interesting place right now. See also https://forum.inaturalist.org/t/does-dna-barcoding-create-a-brave-new-world-in-mycology/52316. My impression is that microscopy is still useful, though I’ve yet to buy a microscope and test that theory.
I don’t personally think that plants are at risk of getting that “bad”. You may disagree with me and say that plants are already that bad, or are getting there. If so, that disagreement would take us back to Chris’ query. 