Reasonably flexing with the spirit of the question - I wouldn’t say their business acumen made me a fan in its own right but I certainly admire and am happy for the fighters who did well financially - including Firpo, Schmeling, Holmes, Foreman etc. So many others, even after the hitting heights, still ended up broke.
This: I can admire a fighter’s (or ex-fighter’s) business acumen or lament their lack thereof and still either be a fan or not a fan of them as a fighter.
I've never become a fan of any fighter because of their business acumen but I do like to see fighters doing well after they've retired. Far too many of them end up with nothing.
I like hearing a boxer doing well after they retire, like Hagler and Holmes but in general it doesn't seem like boxers make the best money decisions sadly! Otherwise I just view it as a sport, I would rather see an exciting fight than a boring one between two accountants
I could care less about their business ventures or how much money they've spent or saved. I don't even care much about how they snore or pass gas, I just care about seeing their talent in the ring.
I would say the closest thing is this current generation of Super Flyweights, because some hype got built a variety of intercontinental fights got made and broadcast widely that in other eras wouldn't have happened. Chocolatito specifically is tricky to promote because the American Nicarguan community is pretty small, no super famous decades old rivalry (like Mexico and Puerto Rico for instance), etc. But I don't think they did that, I think it was Eddie Hearn seeing an opportunity to stage some exciting fights at a huge discount to the what the purse would be if the combatants weren't tiny and deciding to invest in some promotion.
Hard to say how true this is but Canelo is another one. The rumor during the pandemic was that Hearn was only willing to pay for him to fight ODLH, GGG, or certain MMA guys. The story is that he somehow negotiated this much better schedule that he faced (though he had to provide sops in the form of Yildirim and GGG 3). If true, the story is another example of business acumen leading to better fights.