Apple TV introduced a better picture in 2017 with 4K HDR. In 2018, tvOS 12 will add cinematic sound to match.
Apple announced today that tvOS 12 will support the Dolby Atmos soundbar for an audio format that gives movie sound a kind of 3-D effect. The addition of Dolby Atmos makes Apple TV the only streaming device that supports both Dolby Vision and Atmos.