I have a hard idea even imagining why someone would even have 200 games. And have you considered that some of us don't want the social features? Gaming is a solo activity for most of us. And some of us don't have an internet connection fast enough that downloading games makes sense.
I think you're wrong when you say gaming is a solo activity for most people. Online gaming is huge nowadays. You're a very casual gamer. I have 93 games on steam myself and I have a lot of games that I didn't buy from steam. And I have a lot of friends online that I've never met IRL that I play games with. Steam is great.