Except many clubs and even leagues are not getting along just fine. In fact, some European leagues are actually studying the MLS model. Not that the promotion/relegation system will go away in Europe, but for good reasons league and club management are exploring ways the ridiculous cost inflation can potentially be partially contained.
That doesn't mean you'll see La Liga, the Premiership, etc. operate like the MLS full-on, but when only about 4-5 Premier League teams breakeven most years league and club management are considering possible alternatives or bits and pieces of ways other leagues and businesses operate. Somehow, bleeding red isn't always due to insufficient top line revenues.