There is no need to ask a bunch of people on a bodybuilding website when this information is readily available. The wealthiest people in the world are almost all people who started a business that took off. Once you get below that level of wealth, you have real estate developers, oil and gas developers (whether exploration and production, midstream gathering, transportation, etc), investment bankers, entertainers/athletes, etc, etc.
Doctors, lawyers, bankers, corporate types are all pretty much pyramid schemes. In the early years, you make considerably less money than people think you do and you work long hours. The reward is when you make partner and you start to share in the revenues earned by the junior folks who are working their asses off. Bear in mind that the people at the top still work pretty hard (years of working hard kind of ingrains it in you), it’s just that they earn $$$ from the efforts of others as well as their own effort.
Clearly, I am generalizing in the above examples. Quality of life is very important as well. With greater wealth and salary there is usually higher risk in that your revenue streams are typically not as secure as many lower wage careers = higher stress. For example, investment bankers, while they tend to make very good money, one bad year and you are likely out of a job. It can sometimes take a year to land a comparable job. So, if you made $1.0 million one year and then $0 the next year, your average yearly earnings takes a big hit.
Couple that with the fact that there are bigger forces at work that can have a much larger impact on your success in these careers than your personal effort and you get a high-stress lifestyle. That is why the turnover in IB is so large. People burn out or get flushed out with regularity. Ask most IBs what their career goal is and it is usually to make X amount of money by Y age so that they can either retire or go into business for themselves in an unrelated field.
There are also different paths within IB that have different time and effort requirements and different stress levels. Income is typically scaled accordingly.