I work in a California State Park, and iNaturalist is tremendously useful in a wide variety of ways. We encourage volunteers and visitors to take observations, and now have almost 30K observations of 1900 species in the park. If an invasive plant shows up in the park, I can see an iNat observation of it and have it removed before it spreads. If a member of a local tribe has a permit to collect black oak acorns, I can point her to the right spot. If a conservation photographer wants to get a photo of a Western Tanager, I can tell him right where and what time of day people have been seeing them. If a volunteer wants to update our recent wildlife sightings board, we have a list ready made.
But for me personally, the best reason to upload observations is how much I learn from it. Seek gives you a suggestion of what you might be looking at, and that’s usually the end of it. Using iNaturalist, I register a guess as to what I’m seeing, sometimes with the help of the AI, and then other naturalists tell me what I’ve actually found, or help me figure it out. And I can ask them how they know, and what details I should have gotten better pictures of, and why it couldn’t also be this other thing.
And I can look back at my previous observations and say, oh yes, we eventually figured out that the caddisfly I thought was a moth https://www.inaturalist.org/observations/21765821 was Nerophilus californicus and this one has the same striking markings and habitat. When I started using iNat a few years ago I could identify maybe 10 local plants on sight, and now I’d say that’s closer to 250.
But even beyond that, iNat is a community. I’ve used it to recruit volunteers, organize events, make friends, rally support for causes ( https://www.sonomanews.com/article/news/the-species-found-at-sdc/ ), make professional contacts, find an audience for my infantile poetry ( https://forum.inaturalist.org/t/an-ode-to-the-overworked-identifier-with-gratitude-and-apology/2792 ) and so much more.