This has been discussed. I would not be surprised if the new Big Ten/SEC collaborative does exactly this. What I have heard is that criteria will be introduced that requires a certain stadium capacity and average attendance, viewership, enrollment, athletic budget, etc ... that elevates 30-ish programs. Those will qualify for expanded financial opportunities. Others will simply get some standard payout as a simple conference member, but not much beyond that.
Vandy, for example, would get a standard payout for appearing on the SEC Network (just like MS State, South Carolina, etc) and substantially more if on a premier network ... ABC, ESPN, etc and also more for post season. That's not likely to happen, but it could.
It will, as you say, reward those who are continually improving to better play and more attractive fans, but not penalize them if they don't. Water seeks its own level.