Comment by ascagnel_

It's because the leagues (and therefore the teams) make significantly more money when the rights are shared vs. when they're owned by a single entity. For example, the National Hockey League is in the middle of a seven-year, $4.5B deal with ESPN/Disney and Turner/Warner; their prior deal with NBC/Universal was a ten-year, $2B deal. Even adjusting for inflation, it's a huge increase from $200M/year to $640M/year over that decade -- an increase that happened despite cord-cutting accelerating significantly over the decade of the prior deal.

On the other hand, the MLS went to basically a single provider (all matches air on Apple's streaming service, with select on terrestrial TV and/or cable), and the numbers on that are still reportedly somewhat soft if you ignore the skewing presence of Lionel Messi (but that's a whole other discussion, because Apple was also trying to do something different and overpaid for the rights to do so, and that overpay was a part of bringing in Messi).