I have to agree on PlantNet. It is good enough to come up with a general name of a plant (ragwort), that you can then look up in a local plant guidebook to find out the specific variety (common ragwort).
Hopefully, a privacy-friendly phone (ie Apple) manufacturer acquires them and does deep OS integration with the app.
I'm not understanding why you say that being purchased by a phone manufacturer would be better - wouldn't the optimal solution be to expose any features from the OS that the app could need, while leaving the app developers their independence?
I’m trying to understand the business model that PlantNet has. Right now, it’s obviously some sort of exploitative data harvesting - hoarding geotagged plant photos to sell to academic researchers, highlighting hotspots for nature tourism, etc.
I was alluding to Apple in my comment, as they are the ones that have a model for their mobile devices being some sort of knowledge lens. They are very easily capable to eat the cost of maintaining the database without resorting to some sort of exploitative business model.
It does fail sometimes but it's pretty good, and the UI has improved in recent releases.