You would need to get an AppleTV box for your (not so) smart TV

HDMI 2.1 isn’t required for Dolby Atmos. Even HDMI 1.3 cables can support Atmos in many cases

This is really bad advice. It should be set to HDR or Dolby Vision. The screensavers will only play in SDR otherwise and the HDR ones are SO much nicer. SDR content will switch either way match content turned on

It doesn’t support continuity camera