You are not wrong about the amount of money to be made in the finance industry, but when talking about those salaries you have to be very careful.

Hedge fund managers make orders of magnitude more money than their employees. Investment banks work much like law firms, if you are a partner or partner track you can make tons, but frequently that is built on the back of average paid employees.

What would tech company compensation look like if we included Brin/Cook/Zuckerberg?

There are lots and lots of small shops out there that have good but not idiotic compensation packages. The tech companies could (should?) match them if it weren't an ingrained part of the culture not to.