"And maybe it is just that simple - you don't need super high detail to convey presence."

In my experience with various modern VR systems this is absolutely the case. Latency and proper movement tracking is non-negotiable when it comes to achieving an eerie feeling of presence in the simulated virtual world, but rendering detail is far more optional. Nice to have if you're going for true reality, but not required.

If they've nailed the latency and tracking (I haven't used a PSVR so I don't know if they have) the lesser detail will be lost in the noise, sort of like it is now when you compare the PC version of a game (say, the Division, for a contemporary example) to the console versions.

Everyone knows the PC versions of these games are capable of looking better in A/B tests, but many people are perfectly happy with the lesser detailed version.

I buy PC/console releases on console far more often than on PC despite having a powerful enough PC to run new games just because I find avoiding the pitfalls of driver versions, the perfectly standardized voice communications for multiplayer, etc more valuable to me than the extra rendering detail.