I'm glad you brought up Nike, seeing as though they're currently paying over $200m a year to outfit over half of the 130 FBS schools in America. Even though Phil Knight is a Duck, Nike is a business and pays that money as an investment. Paying millions more to send a few kids to a particular school seems meaningless in the grand scheme of things. They would rather use that money to sign Zion Williamson a year earlier than they did, regardless of where he chooses to go to school.
I've seen a few people recommend raising the cost of attendance stipend from $2,500-$4,000 to $10,000. Unfortunately this would only widen competitive imbalance seeing as the schools are the ones paying that. Everyone may think these athletic departments are loaded, but when you have 1-2 revenue generating sports supporting 20+ sports and 600+ student athletes, most of them aren't making money.
The initial cost of attendance stipend weeded out many G5/FCS schools as they couldn't afford to pay it. Over doubling it would mean millions of dollars more (most schools provide it to all student athletes) and I think you'd see poorer Power 5 schools balk. Then it becomes go to Alabama and get my $10k c.o.a. stipend or go somewhere else for less?