Look at Flipkart from India. Valued at over $15Bn USD. They attended the IITs in India yet build a world class company :) So to answer your question, there are people who still make it big despite not having attended the Ivies!!
There have been some efforts to rectify that through quotas, though from anecdotes of colleagues it sounds like it hasn't really been solved (e.g. no proper support system leads to disproportionate dropout rates)
https://www.quora.com/Do-you-think-Scheduled-Castes-SC-Sched...
tbh it is not never ending. From a non wary eye one can celebrate the bansals for building a pvt business valued over 10billion $ but seriously, there is no way they can match that when they become public, there is something called as revenue that they need to generate regularly! Just by offering crazy discounts they might be able to boast that they sold 100000000 MotoG's in one day, but what they don't tell is that they are solely functioning on the money investors are throwing at them also they have around 2Rs loss per 1Re revenue
So just because they built a seemingly large enterprise doesn't build their legacy, there are many many such examples of the so called unicorns who collapsed just because they couldn't gain traction after they hype they generated, take a look at homejoy, they were earning some real heat in their market until they realized they were solving the wrong problem or solving them in the wrong way, so it folded, it won't be long until paytm/flipkart/snapdeal etc etc who have a huge customer acquisition cost fold because their CA >>>> CR customer retention. The sole reason people buy from Flipkart is because it is cheap on flipkart, if the same item is cheaper somewhere else, they buy it from somewhere else, I really don't understand how this is any indication of being in the right business or a measure of being a strong business?
Amazon is the sole major ecommerce provider in US and for 30 long years they didn't become profitable despite being the sole provider, only now did they become profitable, compare that with the complicated scene of Indian ecommerce where there are way more providers and the CoD woes plus marketing costs and the ridiculous "coupons". Some people I know actually think paytm makes money, it is silly, they don't! They are just making people habituated to using and spending their hard earned money on paytm in hopes that they will be regular customers which they won't because the sole premise that people buy from these companies is because of the discounts they provide and nothing else, so when the dust settles down and they can't provide any more discounts, they'll fold.
Warren Buffet and Bill Gates may be considered good for founding a fledgling enterprise because they earn money.
That being said when this bubble will burst a new age will dawn upon their ashes, I think we really need this lesson to make more prudent investors for the better future India!