For almost a decade, NASCAR had something resembling a national fanbase far better than CFB, to the point they built and opened tracks with SRO crowds in Texas, California, Chicago, and Kansas City. But their infatuation was similar to when the Carolina-based NWA wrestling promotion (1987) decided they wanted to be a "big deal" and moved their annual Thanksgiving show in Greensboro, NC (since 1961) to Chicago, and wiped out both towns forever for NWA wrestling.
NASCAR did a similar thing - thanks to NBC and Fox sticking their noses into the racing business - and saying things like, "Fans would rather watch the superspeedway race from California than two races at Rockingham and Martinsville. Oh and why not move Darlington away from Labor Day!"
And the same thing happened to NASCAR as happened to wrestling.
In 2004, NASCAR was getting ready to have a regular season race in Japan and expand worldwide, like maybe they thought they were the NFL. The sport peaked in 2005 - and it has been all downhill ever since. Rules changes, track changes, the same guy winning all the championships, corruption, the whole bit.
College football would do well to learn from the examples of both a fake sport and a real one.
Unfortunately, like every overdose victim who has thousands of people that could serve as a warning, they won't.