I don't think this is entirely true. I don't think it's a matter of how much money from alumni or boosters ND has compared to Bama, more like ND alum are more likely to spend their money on something way more important and impactful than an 18 year old coming to play football for their alma mater.
That's also not what NIL was supposed to be. "Name, Image and Likeness" was supposed to get these young men compensated for schools using their name, number (jersey sales) or likeness (such as a video game) to properly compensate these kids for their own brand that the schools have been profiting off of for decades. The way ND is doing it, asking their players to go out in the community and earn their check, or the way Kyle Hamilton and those boys did it by hustling on the side and creating a nice following through a podcast, is the way NIL was supposed to be done.
Unfortunately, it wasn't/isn't properly regulated and this is now our reality. Some schools have rich ass donors who dgaf about anything but football. That's not ND. Even if you really want it to be.