It's not necessary to identify yourself unless if you claim to be a public figure. But in that case there are better ways of verifying that you are not stealing someone's identity.

Most people are not good at photoshop anyway (the examples you include are obvious fabrications).

Believe it or not several spammers and catfish have been discovered because of that fact.

I have never done an introduction post or disclosed my identity...but I don't need to. I don't claim to be the author of any original public content or pretend to be someone I am not.

There is an advantage when you put a face to your online persona. It's easier for others to relate to you and that helps getting followers.