And appears to possibly only get worse.
https://learning.dolby.com/hc/en-us/articles/4406039180564-Appendix-C-Dolby-Atmos-Delivery-Codecs-
Dolby AC-4 IMS (Immersive Stereo) is a next generation audio Codec. Dolby AC-4 IMS is used to carry Dolby Atmos at extremely low bit rates. Dolby AC-4 IMS uses Binaural metadata created during the Dolby Atmos mastering process to create a bitstream that is compatible with standard stereo playback devices as well as a virtualized immersive Dolby Atmos experience on mobile devices using headphones or speakers.
Spatial coding is not used in the AC-4 IMS encoding process.
As the AC-4 IMS adoption rate increases, it is important for the mixer to also monitor with headphones using the onboard binaural render in the Dolby Atmos Renderer.