Recently, Amazon has been increasingly focusing on audio quality, so using Echo devices as a wireless audio solution for your TV seems like a smart move. Customers with the current generation of Echo and Echo Plus can stream Dolby wireless audio, and customers with Echo Studio can stream Dolby Atmos sound. Of course, it only works with content that you play through a compatible Fire TV device, and since it works in stereo configuration, it may not fit the definition of home theater for some people.
If you want to try this at home, connect your Fire TV device and Echo devices to the same network and Amazon account. Use the Alexa app to select your audio preferences, and then follow the on-screen instructions.
You will need Fire TV Stick 4K, Fire TV (third generation), Fire TV Cube (first generation and US only) or Fire TV Cube (second generation). And at least one of the compatible Echo devices: Echo Dot (third generation), Echo (second or third generation), Echo Plus (first or second generation), Echo Dot with clock, Echo Studio.