However that is a vast mis-understanding of what a lot of the brain power at an investment bank goes towards. It isn't just equities it is fixed-income and economics as well.
But beyond that it isn't just about valuation. It is everything from working on how to actually clear transactions, building dark pools and similar platforms, research and building very real tech on blockchain, building security and infrastructure tooling.
Goldman literally invented a programming language (although it is showing it's age at this point). They make very robust Open Source contributions: https://github.com/goldmansachs/gs-collections (just an example).
Regardless of if what they do is immoral or silly or both, they are building interesting stuff and solving hard problems.
A better organization to direct a dig like that at would someone like Bridgewater, they really are just trying to value equites, and fixed-income.