It takes far less money than a billion dollars be able to make world-changing charitable donations. You could, say, fund a light rail system (yes, even in a decently-sized city) or housing for every homeless person in your home town for vastly less than that.
There's only so much you can invest in yourself and your personal hobbies before there is nothing more you can realistically buy. Any normal, reasonable person, once already confronted with a luxurious lifestyle for themselves and their loves ones that will last forever, looks at all their extra money and decides it would make them feel good to make those world-changing charitable donations. And so they do it.
I'm sure everyone's point of balancing anxiety and lifestyle is different... but any reasonable person, it's WAY before they hit a billion.
In short: a normal person starts wildly giving away their wealth long before they become a billionaire. You have to be some kind of antisocial weirdo not to.
They didn’t “solve” anything. It’s a private medical school with a sub 2% acceptance rate. The kind of people who are going to be attending a school like this are already likely to be far better off than most as many will have accomplished pre-med courses and extracurricular activities to stand out as well as have had financial, scholastic, and other support to have the grades necessary to have a shot at being accepted at such a school.
IOW, exclusive school will likely mostly admit students from families wealthy enough to afford the best education and prep likely to be offered a slot at an exclusive school.
The only thing I’ll grant is that people who do get to this school will have less debt if they are of lesser financial means.
Nothing was “solved”.
E: further thought: this “gift” is giving other mostly well off people a price break. If a lower income family with a student is at this school it’s probably the exception to the rule of who benefits from this gift.