Despite Apple's boasting about 4k, HDR and Dolby Atmos support in Catalina, still is non-existent. In December, 2014 (yes, nearly 6 years ago), wrote the article, why you can't get 4k Netflix on a PC or Mac (Even though they're capable). Since then, Windows 10 has had some in-roads, but it's still not great. macOS has made virtually none.

Service tvOS 4k macOS 4k Windows 10 4k
iTunes Yes Yes* Yes
Netflix Yes No Yes
Hulu Yes No No
HBOGo* No No No
Amazon Prime Yes No Yes
Disney Plus Yes No No***
YouTube Premium Yes No No***
ESPN Yes No Unclear

  • * - Requires Catalina for Dolby Atmos, 4k/HDR.
  • ** - HBOgo does not support 4k.
  • *** - May work with ChromeCast via Windows, YouTube. YouTube's regular service supports 4k Streaming for macOS.