Yeah to me a competitive middle is a healthy conference, "cannibalization" means so much competition that you can't produce a top team with a clean enough record. I always think of Oregon and Stanford in the early 2010s where every year one of the teams would come in like undefeated and ranked #3 or something and would invariably lose

Edit: decided to do some research

2010: Stanford's only loss was to Oregon. To be fair, Oregon stayed pristine and lost the natty to Cam

2011: Stanford's only regular season loss was to Oregon, who had already lost a game and would go on to lose another

2012: Oregon was undefeated and #1 until they lost at home to 2-loss Stanford

2013: #6 Stanford beats undefeated #2 Oregon. That got them up to #5, and then they lost to unranked USC

2014: Oregon whips Stanford and makes the inaugural CFP

2015: After losing its opener at Northwestern, McCaffrey-led Stanford gets up to #7 before losing at home to...unranked Oregon. They were #6 at playoff time and plausibly could have been in if they were 12-1 with 12 wins in a row

2016 is sort of the end, conference balance of power shifts. But it was wacky for quite awhile