Why would an individual buy stocks other than to make money? Certainly not for charity. And if it's just virtue signalling, there are far cheaper ways to feel morally superior.

The companies in the stock market are not primarilay a jobs program. It is not the primary role for companies to pay their workers. Such a system would never work and would collapse.

Virtue signalling about "treating employees well" is shortermist and doesn't consider the higher order effects.