There are far too many teams and leagues in 1A (FBS) to have a singe TV deal. And just think back to when we had one. The BT had all then advantages in the few National games and in the 'regional games.' In case you have forgotten, BT territory was considered by ABC to include the entire northeast down to DC. AS UK was never any good, the Louisville TV market always got BT games. And that deal also promoted the pac excessively, being Rose Bowl paired with the BT..
The best we are going to get, best in terms of the most teams and leagues in a new Top Tier, is 4 leagues. And neither SEC nor BT is going to give up a penny in their regular season TV deals.