Floyd is mainstream in the way that maybe 40-50% know him...and that might be high...but I would guess 10% could name one of his fights. Boxing is a novelty sport here in the states except for diehards. My sons 21 & 19 grew up watching Azumah Nelson and tons of boxing...but it is of no interest to them as adults they favor mma. They know Floyd fought Connor but only because they watch mma. I doubt anyone outside of another Tyson like personality coming along
Yet the USA has way more pro boxers than any other country, about 50-60% of ALL pro boxers are American USA has by far more TV channels showing boxing than any other nation. USA has more boxing gyms than all other nations More big promoters/more money. Etc etc America has everything on a plate for a pro boxer. Most of the people on boxing forums/you tube channels and comments and comments are American. Its not as much of a niche sport as some of you yanks claim. Boxing is a niche sport in almost every country don't forget. Here in the UK theres at least 8-10 more popular spprts. The USA has such a MASSIVE population that even a small minority of people that watch it - is way more than most other countries