Which is partially why we get more diversity of teams playing in the World Series in baseball than we do in the NFL or NBA in their respective championshipsI actually think the salary cap is a good example of a measure used to (at least in theory) maintain competitive balance that kind of does the opposite.
Bad teams pressed against the salary cap are stuck bad with the exception of throwing games for draft picks. Additionally, in the salary capped sports (basketball and football), they come with extensive revenue sharing so cheap owners can make a lot of money without putting a good product on the field.