I've used the launcher function to run video files and it works pretty well, I don't think there's need to support video files in any official capacity because it's not the intention of the app, but if you wanted to use it to organize your video files its entirely possible to group them as-is. For tv shows what I do is add each episode as a separate launch function which you can pick via right click. Pretty intuitive, gets the job done, and it's served me well for organizing my media collection since I first started using Playnite.
