{NSFW} Why do men buy penis enhancement pills?

Is penis size the equivalent of how some women feel about their breast size? I really don’t get it. I mean women can get implants, but it’s pretty much a known fact that such “penis enhancement supplements” don’t tend to work. Yet I’m willing to bet that it’s a multi-million or even billion-dollar industry.

I guess my question is more aimed towards men who are pretty much average in size. Do guys still get insecure about their manhood even if they are “average”?