https://www.polygon.com/2019/2/21/18234737/steam-video-section-closing-pc

Valve is paring down its video offerings on Steam, and will now limit the service to movies that are directly related to video gaming or are adjunctive to ones sold on Steam.

The change may seem a subtle one, but Valve’s announcement wasn’t. A brief note said it had noticed what users had watched — or rather, how much they hadn’t watched — among the free and premium videos available and realized its experiment with the service was at an end.