PS5 drives must also be pre-approved by Sony, supposedly due to strict hardware requirements, like 5.5GB/s[1] sustained bandwidth. I personally think it's silly, sure, bigger numbers mean better performance but I would be surprised if most games wouldn't work perfectly fine with a nowadays average SSD.
Ah no ps5 and xbox both have been designed for fast loading of game textures. Even the new nvidia and amd cards support the same so current games might be okay with slower drives but texture loading has been a bottleneck for 4k gaming which this solves.
With the original Xbox, they used hard drive locking that made it difficult to swap out to a new one. Its been a very long time since I've done it, but I seem to remember having a hard drive powered by a normal ATX PC, then swapping the data cable over from the PC to the Xbox while it was still on to achieve a HDD upgrade (with other steps in the middle that i've all but forgot).
It was a hassle for the 360 as well, you had to plug the drive into a PC first and run a homebrew tool to "bless" the drive so that it would work with the console