But the information on iNaturalist isn’t recorded physically. As I’ve already explained, none of the cases where information was recorded physically are comparable to iNaturalist. The analogy isn’t valid.
You’ve answered your own question. The setting isn’t seemingly less formal, it is less formal. The iNaturalist/user and publisher/author relationships are very different.
You’ve also made my point for me. You gave your publisher a perpetual license to your work. No doubt it was a condition of getting published, but nonetheless that was something you agreed to. With few exceptions*, nobody has given iNaturalist any comparable license. Indeed, nobody has been asked to do so. INaturalist doesn’t have an agreement with their users comparable to the one you have with your publishers.
Perhaps it isn’t, but it should be. The internet’s habit of driving a bulldozer through everyone’s privacy is well documented as are the almost universally negative effects thereof. The “right to be forgotten” is moral principle even more than a legal one, and it trumps any concern about loss of data. And for once I appear to be on the same side as the iNat team. (At least as of five years ago.) I don’t often say this, but they got that one right.
*A few people have a statement on their profile saying they want iNat to keep their data in perpetuity. They are very much the exception and the permission given is explicit. Obviously, I respect their rights just as much as I respect the right of other users to delete everything.