In real life, you can set up businesses with other people, work for businesses, take loans, use derivatives, all kinds of stuff; you aren't limited to simply buying and selling physical goods with whatever coin you have in your pocket.
In real life, setting up a business is extremely risky. Google for "90% of businesses fails" and see for yourself.
Also, it is not that easy to set up a business in the first place. Certainly not as simple as "just take out a loan" when it comes to raising capital. Just look at this forum, so many "ideas guy" with no money to start their own game development team.
Most people are stuck working as employees.