NASCAR attendance crashed after they closed many of the original tracks - or cut dates - and built tracks outside the core southeast market. They also went corporate and priced many fans out. The 2008-11 recession hit them hard, and they have bulldozed stands to lower capacities at some tracks to increase attendance density.
I stopped following NASCAR with any regularity when the "car of tomorrow" common template was introduced. I'd had a long following of stock car racing, including short and dirt tracks around Bham. I know I've shared that at the old Dixie Speedway in Midfield, my Dad was spun out by Bobby Allison, who still dropped down from NASCAR in the late 60's to race decent money features on short tracks. To lose a guy like me to the homogenization and money-grubbing corporate reach of the sport says a lot.
Will college football peak and price out many schools? Probably, absent an agreement to have a NASCAR-like Winston Cup/Busch tiered approach where the SEC/Big 10 and anyone left to compete at that level, followed by a second tier of former Power 5's and other notable G5 teams. They will have to agree to a standardized NIL framework, which of course they won't follow.
RTR,
Tim