No, you add value to their labor and in return get to keep some of it.

Or you can solve some previously unsolved problems which allow you to produce better products for lower costs than your competitors. This is how Carnegie, Rockefeller, Walton, Bernard Kroger, Aaron Montgomery Ward, Richard Warren Sears, etc. all made their fortunes. Even modern tycoons like Jeff Bezos, Elon Musk, Bill Gates, etc.

Can they get too much market power and start stealing from society? Absolutely, that's why we have anti-trust laws. But to see a fortune and assume a theft is to fundamentally misunderstand economics.