A lot goes into who is gonna blow up and be a star especially if you a black american. Not everybody has the same ceiling and sometimes the stars will align for you and sometimes they won't and then you gotta add in timing.
-Have an entertaining style that makes for good fights (Broner, Crawford, Thurman, PED, Wilder, lot guys do this part)
-Fight often (lot of guys don't in this era)
-have a great personality that is engaging to casuals (You can be a so called nice guy and still be off putting to a lot of people just like you can be a likeable a$$hole)
-Win your big fights (this is where guys like Zab and Broner failed at)
-Fight good competition (this doesn't always happen enough, but some guys are pretty consistent with this)
-Target the hood with your promotion/marketing....Try to appear in popular rap videos, get tv show appearances, be at events, do a lot of interviews,do meet and greets, radio etc...
- Give the country a chance to see you by fighting everywhere, not just Barclays, Vegas, and Cali. Hit up Texas, ATL, FLA, CHI, etc...
I know the above list is a lot to cover, but it's not impossible. Roy did most of that shyt for a while and was popular as hell in his time and made good money. Ditto for Tyson and Holyfield. Most nikkas now ain't doing half the shyt on that list or they'll be real good in one area, but bad in another.
Guys like Thurman, Wilder, and Crawford should be house hold names to casuals. Yeah you can make a few excuses for them, but at the end of the day, I honestly don't think dudes are doing everything they possibly can to be bigger in the sport. Hell, Broner is damn near there. All he has to do is win the big one and minimize the fukkery.