While I agree that all these PC storefronts are a complete PITA, none of them charge a subscription fee like these streaming TV services do. The added cost is in terms CPU, RAM and convenience.

The multitude of stores is proving very difficult for independent developers that would ideally release on every store, because each one comes with different APIs, DRM and community features that require bespoke integrations in both the game and game server (if you have one). The documentation for this stuff is rarely great due in part to the secrecy surrounding the industry, and the speed at which publishers are knocking their own stores together.