I don't wear camo because it doesn't help me.
But it greatly depends on what and where you're shooting.
I shoot at the coast and shore line, where camo doesn't do anything for me. I look normal in khakis and a blur shirt there, or even white. Doesn't seem to matter. In this wide open terrain, we're obvious no matter what. I tend to get pretty close even then, simply because they're used to people in these areas where I am. But approach is everything here. If I walk fast, versus slow, if my camera is already raised, or if I approach and then raise it, etc, play bigger roles in the attention I get from the birds at the shore, than what I wear.
For every thing else, I just get there before the birds, and wait. Or I sit in a blind so that my movement and existence is masked. I find the blind works best over all.