The way you talk there's zero need for a playoff at all. Let's just go ahead and crown LSU champions right now. /S.
You have to look beyond JUST the playoff itself. What about how it would benefit the college football season as a whole? Surely you realize that by making the 5 power conference winners automatic bids into the playoffs, it makes winning your conference that much more important, making the individual conference games that much more important. Making the college football season as a whole more exciting.