It's a feasible strategy - there are thousands of entrepreneurs who did just that: do an MSc/PhD in Finance/Economics (or these days just any old STEM subject), join a bank's trading floor or a big investment company, put aside 2-3 million in 10-15 years - then get out of the rat race and create a start-up or become an angel investor.
Of course there's ten times more people who inherit a million or two of seed capital instead...
People buy things which make their life better than it was before they bought the product or service. The magnitude is not important. You now know 'money', if you have the dev knowledge GO BUILD SOMETHING OF VALUE!
Of course there's ten times more people who inherit a million or two of seed capital instead...