there's a thread that broke down the graphics frame calls that didn't even get into the compute shaders and found plenty to be concerned about in terms of being unoptimized.
It's not a question that odyssey's framerate is due to poor implementation rather than technical requirements. You can witness it doing things that will slow it down for no apparent reason directly.
That hits everyone regardless of hardware. To varying degrees, but still.
The need for high framerates is more about input latency (which is extremely important in twitch based combat / fps scenarios). 60fps vs 90fps is a 30% difference in latency but more importantly, that's still a significant amount of time that it is noticeable and meaningful - even if the monitor can only display 60.
It's less about what the eye is seeing and more about what the response on the screen is doing in relation to what your hands are doing to your mouse/keyboard/hotas etc.
Plus, taking a hit in space - even if it's still above your threshhold of finding acceptable can be extremely impactful to VR which requires a stable 90fps to be ideal. Something hardly possible in roid fields now - much less with other assets such as planets / etc.
edit: basically it comes down to this simple math
if a graphics frame takes 1/60th of a second to process then there is 59/60'ths of a second to do everything else it needs to do to get ready for the next graphics frame. Now, if there is a 25% chance that 59/60ths is not enough time, we'll miss that monitor refresh and have to wait an entire 1/60th of a second + our overrun to draw the graphics frame. doubling the latency the user sees to something even larger than 1/30th of a second.
That's a big deal.
Now, if the graphics frame takes say 1/120th of a second to process, then there is 119/120 of a second to do everything else in. Maybe now there is only a 5% chance that that isn't enough time. But the monitor is still only 60fps. Here, even if we hit that 5% chance, our graphics frame can be drawn before the next monitor refresh rate and not have to take the additional penalty. Our latency is hardly impacted. We have effectively a 50% buffer to absorb frame rate variances caused by the rest of the game. 90fps caps on 60fps monitors have a 30% buffer to absorb these variances.
Faster monitors make this additional "missed vsync" issue less of one, but most people are rocking 60fps monitors and that can easily be a noticable change in latency when it's missed. Especially since those misses tend to cross multiple cycles and aren't just 1 off aberrations.