You act like being an investor is like a secret society where everyone is making easy money and the workers are the fools. Investing is a major risk and sometimes fails spectacularly.
Some amount of subsidizing "[economically] useless" people is a matter of society taking care of their lowest. Disabled people, people with IQ < 100, people who took good chances and had bad dice outcomes etc.
They already do, you are subsidising owners/shareholders a lot more than you'll ever subsidise your "useless" colleagues.