First, in most companies it's very hard to say who exactly managed to increase the profit. Is it you who came up with the idea? Is it your boss who picked this specific idea out of fifty other ideas you came up with last week? Is it the QA team who managed to catch the bug which would've erased all the profits? Is it HR who hired you among other candidates?
Second, no, the remaining is not $460k. In a Big Greedy Corporation I work an average annual cost of employee in "primary" location is around $200k (pre-covid). It includes office space, technology, infrastructure, salary, taxes, fees, insurances and so on.
Third, that's the premium the company gets for the risk. Intern will get his salary no matter what. The company makes a bet though. You want to own part of that risk? Build your own company.