There may be web content you want to watch on TV, but no app/channel exists. The downloadhelper add-on may be the tool to use. The Downloader browser add-on extracts the .mp4 for downloading to a storage device. Download to a USB thumbdrive and insert directly into the USB port of your TV for direct playback. Many TV’s support .mp4 playback
Download helper is one of many add-ons, tools available.
You likely will find another you like better.