You are kind of working with a heavily biased sample group here, almost 10:1 or greater. Of the 30+ discs or so, I appear to have, all bar I think 4 or 5 are Atmos.
I believe that there are good and bad examples in both formats. In Dts:X Atomic Blonde and Crimson Peak are good examples. Pitch Perfect 3 is a bad one. I know from the Cinema experience Fast and Furious 8 was a bad Atmos example and a good Dts:X bluray.
I think that Mad Max Fury Road, Kong Skull Island, Ready Player One are good Atmos examples. The Mummy or John Wick are much less impressive.
Funnily enough last night, by mistake I watched the first half of Terminator Genisys up mixed by Neural X and the second half in it's native Atmos. Honestly if I had not noticed the display I would not have known or been able to tell you which was which.
Given that most Cinemas appear, at least in the west, to be set up only for Atmos it would then be odd that formats would automatically be switched for the bluray or UHD release. China, at least from the Dts list, appears to be the reverse.
I have not been able to watch either Gravity or Oblivion in any formats other than Dts HDMA and so I will not comment if they are good, bad or anywhere near the best examples of a format. I do know that even the bad or less than stellar discs in either format have their moments. Also how engaging the film is in the first place will likely skew the impression of the audio. Nothing in A Quiet Place is encouraging me to re-watch this anytime soon.
Perhaps some UHD discs which have both mixes present would be a good place to start.