Seems to go way back to the B&W movie era - men in tuxedos, women in evening gowns and boas - glamorous socialites dressed to the nines, watching a couple buys beat each other up. Sometimes the MC is in a tux. I don’t get how that whole package goes together.
As for boxing and wrestling in particular I have no idea. But I’d just point out wearing a well fitting suit of fine clothes is its own reward. Even if you just get thrift store hand me downs, tailoring is surprisingly affordable. Few things feel as good as a well cut suit!
Edit: Lol everyone hating on a tux!?!?
TBH I’ll take shorts and an aloha shirt anytime.