It's not a scam for you but rather a scam for society at large. Making money purely by owning some revenue generating asset, while not providing any service yourself is doesn't work if every single person does it. Many people who work at companies on the S&P500 aren't paid enough to having savings to invest. The money the company saves on employee salaries are shown as profits which result in the "passive income" that you're making.
I don't 100% agree with the logic because it doesn't account for improvements in productivity but I think it roughly translates especially in some late stage capitalism cases where company profits grow despite lower productivity (eg. layoffs).
Perhaps those who aren’t the investors benefit by being invested in, indirectly. They are benefitting from a government running on money from bonds, and possibly employed by a business fueled by some form of debt.
Why does the evil conspiracy that's exploiting those poor workers let nobodies like me (and presumably you) buy shares that let us participate on equal terms in their profits?
The aristocrats of old never felt the need to share the wealth like that, did they?
I don't 100% agree with the logic because it doesn't account for improvements in productivity but I think it roughly translates especially in some late stage capitalism cases where company profits grow despite lower productivity (eg. layoffs).