What you would have without the draft is a set-up like European soccer. The big money teams would get all the the good players. In European soccer, even when a "small" team gets lucky and finds a diamond in the rough, he ends up leaving for a big team within a few years. Literally every year the same 4 or 5 teams finish in the top 5.
It's a completely different dynamic than the NFL. It works over there because that's what they are used to--people passionately support their small teams even though they have no chance to win the title. They are just happy when their team finishes higher than expected, or even if they just avoid relegation.
I don't think that would work here.