You are listening to it wrong.
There is actually a HUGE difference in the sound, providing you have the gear and are watching a streaming service that supports both Dolby 5.1 (and above) AND spatial audio. These services include Apple TV+, Hulu, Disney+, Vudu, and Peacock/Paramount+ when they launch. Spatial audio is not currently available on Netflix or Amazon Prime.
You also will need an IOS device - iPhone or iPad. Current Apple TVs and Macs do not yet have the feature, although it's very likely they will in next generation software and/or hardware.
The difference is profound. Without it, you are listening to movie soundtracks in stereo. With it, you are listening to Dolby Atmos! Watch Avengers Endgame or an episode of Mandalorian. Spatial audio turns your headphones into a theater style listening environment. Watch/listen to some content for about half an hour and then switch off the spatial audio. Yuck!
I appreciate your response, but may I suggest that before saying that I've been doing it wrong you actually read my post? I tested spatial audio with Air Pods Pro with the latest firmware, I used an iPhone X (which supports spatial audio) with the latest iOS, and I watched scenes of Greyhound on Apple TV +. I'm not sure what I did wrong? The difference was not profound and in fact was limited to the effect when moving my head. There was no surround sound.
From reading what people are posting what I'm getting is that some people say spatial audio is revolutionary and amazing, and others say that it's really just the effect of the sound coming from the device (which is what I'm experiencing). This makes me wonder if the people who say it's amazing are amazed by the sound coming from the device effect and there is in fact no surround effect, or if the people who say it's amazing are watching different content than the ones who, like me, don't hear any surround effect. Which is why I was asking for specifically what people are using/watchign when they experience surround sound NOT the head tracking/sound coming from the device thing.