Which investment vehicles are those?
You cannot in general invest money into vehicles which earn a good return but which are divorced from the real world. Imagine if you invest in a company like Apple. Apple developed products like the iPod and iPhone, and the company's value comes from the fact that 500 million people gave their money to Apple in exchange for an iPhone. Apple's $233 billion dollar revenue, and resulting net income, leads to their valuation, which leads to the return on our hypothetical investment.
The investment profits because Apple developed a useful product that people chose to spend money on - the people who bought the products benefited, and the investor benefited from a return. Everyone is better off, and the standard of living has risen. Technology makes things cheaper over time, so that more people can afford such devices. A vast majority of people living in poverty in America own cell phones.
Can you describe how these investment vehicles work such that they're earning a return while being disconnected from the real world? Where does the money come from for the returns?