They have:

A. Preferential admissions for student-athletes. Like, very preferential (although still requiring pretty decent academics given how high the standards for normal admissions are to start).

B. Need-based aid available regardless of athlete status that is so generous that it ends up benefiting significant numbers of student-athletes.

The stories of someone's neighbor's brother's cousin who makes $1 million a year but had their kid go to Princeton for free because he's so good at football are self-serving fabrications.

My wife coached in the Ivy League for a decade. I currently work in the Ivy League. My social circle is largely comprised of Ivy League coaches. The stories about stealth athletic scholarships are simply not how it works.

Preferred admissions for athletes is definitely under fire at some Ivies…also likely the reason Stanford tried to cut half its athletics programs.