Then the only difference is game day revenue. A good portion of the added teams were getting 8k fans when they were in a lower division. Some current MLS teams would still get 20k fans turn up if relegated.

Relegation can actually be fun. After a year of poor results, you can often become a team that wins regularly again. If you still lose regularly after relegation, perhaps the ownership needs to change its philosophy.

Some sort of guarantee for the owners so the move down doesn't crush them, but there needs to be some sort of incentive to fight against relegation.

I can totally imagine, cough Fire ownership, tanking, being fine with going down a division, still cashing MLS checks, and not turning around and investing said money in the team, because of the buffer. This is what happens when the team is an investment and not a passion project.

After you drop down, you still get the PL bump but it's lower, then it's lowered again the following 2 years while you're still out.