THAT's why you go to an Ivy. It's where the successful go.
I'd rephrase that as 'going to an Ivy (or equal non Ivy notable school like Stanford) - gives you - all things equal - a better chance of success' (by various points made by others who have replied to the parent comment).
Now what's interesting is the parent comment 'why would anyone ... a joke' clearly shows that they don't understand at all the value or branding. As if it's some type of mass delusion of stupid people.
Interesting that you place such a high value on branding compared to actually being able to do your job.
So the additional competency from direct instruction is negligible. That doesn't mean that the value of attending a top-tier university is negligible, because the direct instructional education is only a small part of what someone gains access to at a university.
There's the social network aspect: There is a lot of value in having personal connections with other successful people. People need business partners, investors, advisors, etc. in order to be successful, and top tier universities intermingle you with others who are likely to be helpful in those regards. At top tier universities, the majority of people you interact with will either talented, wealthy, or both. At a lower tier university, the pool is far more diluted, reducing the utility of your social network in pursuing success.
There's the branding advantage: if you're choosing between two people, and one has someone you trust vouching for them that they're competent, and the other doesn't, you're going to go with the first person every single time. A top-tier university is basically that third party, vouching for its graduates: they're more likely to be successful, and people want to surround themselves with successful people.
And then there's the educational advantage: If you're surrounded by other smart, motivated people, you're going to gain real educational advantages by cooperating with them. You learn from each other, bounce ideas off each other, etc. If you're by far the smartest person in the room, you don't get nearly the same added value out of your education. At a top-tier university, you're going to be surrounded by substantially more high-quality students than at a lower-tier school.
And yeah, convincing people to give you money is BY DEFINITION valuable. As measured by the value of the money they're giving you.