This isn't the question.

The question is how much value do they add? If it's more than the money they're making, the people paying them are stealing. You don't like this because it makes it impossible to make money as a capitalist, but that's the entire argument. Making money as a capitalist is always unethical, because it necessarily involves stealing the value of someone else's labor.

Just because you can pay someone $1 to do something that makes you $10 doesn't mean it's ethical. It isn't, ever.