iNaturalist is sometimes used by our ecologists/biologists as a starting point for collating occurrence data.
The iNaturalist data itself is likely specifically being pulled from gbif. Then they go private/specialty databases that have more spatially and taxonomically accurate records.
But iNaturalist data is often not considered high quality enough to be publishable by itself (wide brush statement) in my field of plant conservation.
We've tried to have some conversations with iNaturalist and they weren't really interest in talking, gave me pause on what their motives as an organization are.
But conservation tools are few and far between, and iNaturalist is a really powerful tool for initial data exploration.