Obviously, there are also some people in cybersecurity who oversell not for the greater good, but only to further their careers... and even those who are honest and would prefer not to self-promote like that, are sort of forced to, because visibility can matter as much (if not more than) expertise when trying to find a job in cybersecurity, as you'll look like an underachiever if you don't oversell yourself like everybody else.
There are a few “social media famous” cybersecurity folks really worth their salt who didn’t immediately dumpster their morals and skills at the first sign of an ego boost.
People like Krebs, Allison Nixon, Joanna Rutkowska.
Most of them though are just addicted to likes as it’s become a core part of their self worth.
Both of them are well known in cybersecurity but are very different people with very different reputations.
The people you hear from are famous personalities... That's the nature of being a famous personality. There are plenty of us who are just normal people with opinions of our own and no desire to cultivate a public name or face for ourselves...