Once again this is just playing into silly stereotypes. The sort of positions you're describing, at least in cases where it's remotely desirable, are stupidly competitive - substantially moreso than e.g. FAANG positions. And these positions, particularly in finance are absolutely brutal, and completely unfit for the overwhelming majority of people. It's not like you flash a degree and you're off to a life of luxury.
I don’t think you need to flash a degree you simply need to get in to get a life of luxury. It’s not like I can go to the Yale club in NYC.
No, you need to be (1) absolutely top tier talent and generally be willing to (2) live your job. Finance is not cushy. It's cut-throat, ridiculously competitive, extremely intensive, and very results oriented (to a fault - see: Taleb). Obviously having a nice school and a good network will obviously give you a better than average chance at getting your foot in the door, but nothing beyond that.
The main reason you see a disproportionate number of people with nice sounding names on their resume in high positions is because to get that nice sounding name on your resume, you already needed to be an elite academic outlier before joining them.
Like imagine I started a basketball school - and was able to get a disproportionate share of people 6'6" or taller to enroll. I'm going to be pumping out a disproportionate share of NBA professionals, regardless of what my school does. Not because of my school, not because of some special hook-up with the NBA, but because of my ability to grab a disproportionate share of 6'6" types who, in turn, make up a disproportionate share of world class basketball players.
> Not because of my school, not because of some special hook-up with the NBA, but because of my ability to grab a disproportionate share of 6'6" types who, in turn, make up a disproportionate share of world class basketball players.
But you need to be clear about what that actually means in the context of finance or consulting. Because if it's building relationships and bringing in clients, your major has very little to do with it than a function of your social class as the accumulation of the enviroment you're brought up in. There are millions in China or India who could probably do the grunt work in IB, but it's highly doubtful their cultural differences, especially if they come from working middle/working class will impress clients in the same way as someone with a marginally worse working ethic but speaking the same language and a charismatic personality that can pull in others. That's talent in it's own way, but unrelated to academic achivements.
You're going to need to define what you mean by class. It's an exceptional amorphous term and I don't see your perspective here. You will find people from countless "class" backgrounds at top schools, and even in industry there's a wealth of actual diversity on this front. For instance Tim Cook, the progeny of a shipyard worker, graduated from the prestigious Robertsdale High School [1] whose Wiki leaves me with few nuggets of knowledge about the school other than "During a school football pep rally for the Robertsdale Golden Bears to go against the Spanish Fort Toros, students were seen holding Trump flags and a sign that read 'Put the panic back in Hispanic.'" Even at places like Goldman, Lloyd Blankfein [2] is the former CEO and still the senior chairman at Goldman. He grew up in the projects in NYC. Daddy was a postal worker, mommy a receptionist.
The only common denominator you find in these individuals is being the academic equivalent of our school of 6'6" types.
[1] - https://en.wikipedia.org/wiki/Tim_Cook
[2] - https://en.wikipedia.org/wiki/Lloyd_Blankfein