"US sports" may say that parity is essential, but TV ratings don't really bear out and pundits have pointed this out for years. The NBA finals last year saw an overall drop in viewership from the previous year largely because the Thunder and Pacers are not big-market, traditionally dominant teams. Sports is modern mythology creation and the big teams dominate the mythology.

The biggest difference between the Premier League and American leagues is the promotion/relegation system, which automatically demotes the worst teams at the end of the season down to the lower league. American leagues are constantly talking about how to prevent tanking, and pro/rel is an obvious solution to the problem but of course American owners don't want to see it here because they're guaranteed league participation no matter what. Instead, the American league system incentivizes poor team management because there's no real risk by being terrible.