I don’t see it that way, I don’t think blacks are more prone to gambling that whites or any other race.
The fact is, millions of Americans of all races like to have money on sports they watch.
Popularity of the NFL is in a large degree the result of gambling, it’s the easiest sport to understand in gambling terms, plus you have football games on multiple days per week, if you consider college football.
I will say sports gambling is the easiest sport to bet on, you can go to a sports book inside a casino or you can bet online via a website or a lot of people use a phone app to place bets.
The sports books have gotten very creative in coming up with ways to entice people to bet on sports, things like in game parlays, propositional bets, etc., have been very successful to get people to bet on the outcome of something where the odds work totally against the gambler and for the house.