The UFC has its problems, but one stands out as more serious and scary than the rest: Fewer and fewer people are interested in what it’s selling. Even as UFC president Dana White touts his company’s record profitability in 2017, there’s no getting around the basic fact that the company isn’t doing well in the medium and long term. By several different metrics, the UFC’s audience is declining. Moreover, if the ubiquitous commercials for male vitality products like Nugenix during broadcasts weren’t a big enough clue, the audience that remains is aging out of the coveted youth demographic that the promotion used to sell itself to advertisers for so long. Anecdotally, fan enthusiasm seems to be at a low ebb. But every actual metric suggests that things are even worse than they…