That was mostly a 70s thing

Plenty of the "little 8" teams made the Rose Bowl.

Iowa, Illinois , Wisconsin, Northwestern Michigan State all made it to the Rose Bowl in 80s and 90. They were national championship contenders for a for a brief moment. Such teams have less chance in this playoff system. That is not just correlation. They are not set up to compete with the heavy weights through a playoff

The 60s were even more balanced competitively.

Michigan was able to win a National championship too. Not likely to happen now.

Learn some history.