Well to be fair that slow drive performs similarly to the PS5s if you didn't know. However put in a slow GEN3 drive and I'm pretty sure it might be a lot slower.
Anyways I don't see how this is a mark against the PS5s SSD since you need a similar drive to achieve that level of performance. Now if you could do the same with a 2GB/s drive that is definitely a disaster.
Mostly agreed, but I think it depends a lot on the requirements of the game itself. Not every game streaming data off the PS5 SSD solution is going to do so at 5.5 GB/s, or anywhere near that. Even for games that might do so, their rate of doing so could vary greatly both in terms of overall accesses at that bandwidth and duration per access at that bandwidth.
So for some games you probably could get the same results with a 2 GB/s drive. Outside of maximum bandwidth there's actually not much difference between a Gen 3 and Gen 4 NVMe drive, as they both operate on the same NVMe specification. Or better to say, the PCIe bus interface does not determine what NVMe specification a peripheral drive uses, because all of NVMe "generation 1"s features are generally compatible with both PCI and PCIe, regardless of the gen of at least PCIe (to my knowledge, tho PCIe Gen 1 & 2 use 8b/10b encoding which would affect performance a ton).
For example, bit encoding is the same (128b/130b) on both; if Gen 3 PCIe were still 8b/10b for example then yeah that would create a massive performative difference but that isn't the case. If however either of these consoles used an NVMe 2.0-speced drive and users tried installing NVMe 1.0-speced drives, you would have (potentially) major penalties in performance for the 1.0-speced drives. 2.0-speced drives aren't set to release on the market for a while tho.
NVMe 2.0 information