Platforms like SteemIt actually generate real value, in the form of blog posts and comments, which is captured in the STEEM token. The more STEEM tokens you have, the greater your influence on the platform. It's a mini-economic model that's designed to attract more users and generate demand for the token. Games also produce value in the form of leveled-up characters, extracted resources, construction, etc which can be captured into an in-game token, leading to a virtuous cycle of more demand.

Welcome to Steem, by the way :)