Yes. They do this in a lot of ways.

- Connections: industry, hires, investors

- Investing themselves into the company (bringing capital to help you grow)

- Domain specific knowledge. Hopefully they know the industry better than anyone.

- Management. Do not underestimate how far good management can go. It can really be a productivity multiplier - but the other way is true, too. If you have bad management, you're going to kill productivity.