The game streaming device first launched back in 2015, with the intention of bringing PC games further away from the actual system. Simply put, as long as your PC has Steam installed and you have a decent internet connection, streaming game directly to your TV is practically a no-brainer.
That said, the new Steam Link App makes it so that you can now do away with the physical product. That said, there are a couple of caveats with the app. The first is that you can only stream your games to your mobile device. Second, controller compatibility is still a little buggy, especially with the Xbox controller. Of course, you can still stream your games to a TV without a physical hub. But at this point, that would require you to own a Samsung’s Q Series TVs; one of the only TV series that ships out with Steam Link integration pre-installed. (Source: Steam) Edited by John Law