I've been having a play and if I force the PS5 to output at 1080p the image quality is improved. I still just think the game looks better on the Pro. It could be in part due to fake HDR which seems to mess with the UI on Elite Dangerous on the PS5, on the PS4 Pro it's running in it's native SDR mode. The PS5 outputs everything in HDR even when the original source does not support it. It's not a problem for most PS4 Pro games on the PS5 because, yes you guessed it they support native HDR. Elite never did and is just forced through an HDR container which in my opinion looks worse. It seriously over saturates the image (seen on the UI orange especially) and changing the preferences in game cannot fix it.
I might have a play tomorrow and disable HDR and 2160p on the PS5. It might look better. Should really not need to jump through hoops.
Quality mode is broken on both. The image quality is something else as hopefully explained above.
I've read that the "forced" HDR is really bad on non-HDR games, and once enabled the HDR stays so even in SDR games. But I still use a 27" BENQ monitor at 1080p, which is a non HDR monitor, and the HDR option is off in PS5 settings. So at least in my particular case, I am not sure the HDR has any impact on quality mode.
But there still is something absolutely off with it, since this monitor I used also for PS4 (not Pro) and definitely the UI looked cleaner, not as blurry as it does now. So I don't know what is going on, and FDEV definitely will not say anything as they have other things to take care of now.
And one more thing, today I landed on a planet to scan some biologicals, and it was a combo down there, the fumaroles and in between those, some huge crystals as well. I have to say that from above, like 30-40 meters I had some horrible frame rate drops in quality mode. The fumes, the crystals, and fumaroles, they all brought this game on PS5 down to 20ish something FPS. Switched it to performance, the image wasn't as clear, but no frame drops. All this in solo play.
So ok, quality is really messed up; I don't even want to imagine what frame drops we'll have when Odyssey hits. I think it'll be pretty bad, quality-wise since it's designed to run on PS4.