Digital Foundry tested Ratchet & Clanck: Rift Apart per PS5 with a SSD extra much slower than recommended, still managing to run it perfectly. The comparison between the WD SN750 SE (the underperforming SSD) and the much more powerful WD SN850 shows nearly equivalent performance in game loads.
The fact that the WD SN750 SE manages to run Ratchet & Clank Rift Apart perfectly is the confirmation that the game does not necessarily require the ultra-fast PS5 SSD to exist, as also stated by a developer. This is not to say that it does not benefit in some way from the presence of an SSD, but only that stating the impossibility of making it go to other systems due to dimensional jumps is an exaggeration.
As we said, even the loading times do not suffer collapses on the slower SSD which, on the contrary, shows minimal differences compared to the other (we are talking about a few decimals of a second). Where performance tarnishes and the fastest SSD stands out is in the transfer of games to and from SSD, where there are gaps of many minutes. Nothing compromising, considering that these are operations that are carried out only once, but it is fair to point out.