FCS was 16 and expanded to 24. I am not a huge fan. I think 16 is fine, but they want more teams for more eyes and more dollars. It isn't so much about participation as it is about the ability to draw TV ratings and revenue. Every sport is doing this now.
March Madness used to be 64 teams. Now there are multiple play in games because watching Hofstra play Minnesota for the privilege of a 12th seed is must see TV. UEFA now has Champions League, Europa League and Conference League tournaments. What smore, they've expanded the amount of teams in all of them, too. Yes, let's watch Real Madrid destroy some club near Prague in the group stages because I've got the free time.
Whatever. Notre Dame wins a National Championship, I'm not going to care, but that's where my interest lies.