To affect enough football teams ie 16-32+ the importance of the football season shifts heavily to the end. We already have a ranking system that works for 25 teams. The playoff can expand, but it shouldn't dominate.
Also I don't want to end up with something like March madness where the final four are the only real champions and the rest just get the participation trophy.
I would add to that- can we not already have a "real champion"?