Currently your options are the catchily-named Chromecast with Google TV HD, Chromecast with Google TV 4K and, in some regions, the Google TV Streamer. So what's the difference between these options, ...
Google Chromecast is built right into the TV ... The Amazon Fire TV 50-inch 4-Series 4K TV offers a great 4K picture with support for HDR10, HLG, as well as Dolby Digital Plus.
the Google TV Streamer, its existing Chromecast devices will be no more, so get them while you can. It might be a couple of years old, but Apple TV 4K still has the simplest, most consistent ...