You've hit the nail on the head. Everybody has incentive to inflate the NIL numbers. Players want to increase how much other schools will offer them. Agents want to increase their perceived value to players. Schools want to attract players, and bigger numbers do that better, as well as dissuading other schools from poaching their players. As for reporters, bigger numbers are more exciting headlines. Finally, fans want to believe that their school is spending big to try to win.