Patents are tricky. They only last twenty years, but they actually probably have the opposite effect to what you're thinking they do.

Consider the situation where patents didn't exist. I invent something cool. Then I try to start selling it. Well, someone from a company notices my widget idea the moment it hits the market. Or, the company I ask to manufacture my widget, with basic runs easily costing over $100,000 for say injection molded parts, decides that instead of me selling it, they will just sell it themselves, or even provide the drawings to a company they normally get hired by.

Aaaand now I spent money developing this widget, time, effort, but now you won't see a dime. Guess I'll just not invent something next time.

What if I can patent my widget instead?

Now the manufacturing company can only produce it with my consent for twenty years. And now if a company wants to cash in on my widget, they have to buy it from me. Now I have a huge incentive to invent, innovate, and design, because I can either produce it myself, or I can get a fat stack of cash for it from someone who will take over for me while I continue to innovate.

The public facing nature of patents also lets people innovate off of each other even without violating patents by spreading research and design time, while still encouraging innovation in our current economic system.

In other words, patents protect 'the little guy' a lot more than you realize. There are issues with patents, such as a big company buying socially beneficial tech and then burying it for the next twenty years. This has happened many times. It's a problem.