The point of something like Atmos is that you don't need to have a speaker in the appropriate place. Modern surround can do object-based sound imaging, using combinations of the speakers around you to simulate something in a direction where there is no speaker: between speakers, above, below, whatever.
And you don't need some kind of acoustic lab setup to achieve this, you just need a good setup with the speakers spread out in a recommended orientation and accurate system calibration. Put some care and effort into the setup and have things configured properly and it'll be a great experience. This is, again, if you're in a place without a lot of ambient noise.
A well set-up atmos system is great of course, but there are limitations in how it works.
the system is calibrated for a listening position. You can get more seating positions but you need to add speakers in order to get a good frequency response across the different positions. Which is why a cinema will have 32 or even 62 speakers.
Also the frequency response will drastically change just from the room modes. Bass will change a huge amount for example as you get closer to a wall. Yes you can use DSP but it can only do so much. Also most speakers have pretty drastic frequency changes as you move off-axis from the tweeter. Which is why you'll have your speakers pointed directly at your listening position. I suppose they could be mounted on motorised gimbals.
Home atmos is actually not the same as cinema atmos. And even in the cinema, most of what's heard is in the Bed layer, and the objects are a much lower bitrate than the bed layer. If you could only hear the objects it would sound quite bad. I believe that you don't even have objects activate until you have 5.1.4 speakers, or it can just use the bed, but that may be wrong.
so the PS5 is outputting a bed layer to the avr.
you could theoretically track your movement through the room and adjust trim and rotate the bed layer as you move, to match your head position, however because surround sound relies on very exact timing to fool the brain, and that's why speakers are ideally equidistant from you, the further you get from a speaker, the more the whole sound output from all speakers would have to be delayed. So you would end up with sound not matching the video by a fraction of a second, which is what the illusion is based on.
Probably the biggest thing you'd miss out on when not using binaural audio is the ability to use HRTF. With headphones using binaural audio you can simulate a sound being very close to your ear. You can simulate a mouth whispering very close to your ear, at a very specific distance and position. That is something you can't do with a surround speaker setup. Sound cannot come close, it always appears to be some distance away. If you could sit in a cinema and hear a whisper in your ear, or a car motor behind your head, or even a sound inside your head, that would be a game changer.
I will definitely be using my surround speakers to play some games that I'll be seated in, like GT7. Some things can't be replicated by headphones, you can't beat a big subwoofer and speakers for that kind of sound imo.