If it's nothing special why do PC games not load in 2 seconds? Why to PC games still have loading sections during a game? Why do PCs need direct storage and/or the RTX IO to match or exceed what the PS5 is doing?
Software, not hardware. The software I/O stack in Windows is geared towards access characteristics of HDDs which is non-optimal for SSDs. On top of that, games have to be written to take advantage of the SSD. If you look at BC titles on PS5, they basically load similar to a PC with any old SSD. Things improve on PS5 when they take advantage of the more advanced compression available in Sony's PS5 SDK. And then when the PS5 I/O stack is specifically targeted by a game like Ratchet and Clank you finally see everything come together, hardware and software.
On PC, you won't have a comparable software I/O stack until Direct Storage comes out. As well, games aren't leveraging compression that is nearly as advanced as currently used on PS5. Sony really hit it out of the park when they made it so easy to use advanced compression in their PS5 SDK. Microsoft could learn a thing or two from Sony there.
And even then, you aren't going to see really dramatic speedups on PC until games are written to leverage SSDs through Direct Storage, but that's no different from PS5. That said, there's at least one title on PC that is written to take advantage of SSDs and it massively reduced loading times in that game compared to when it was written to access storage on PCs in a conventional way.
Considering, that Sony even recommends just a 5.5 GB/s NVME drive for PS5 for similar experience to the internal SSD. It does bring into question when (or if) we'll see something that won't run on a "good" 5.5 GB/s NVME drive (one that is well cooled with an well implemented drive firmware) just as fast as the internal drive.
There is one bit of hardware that is in the PS5 that we're unlikely to ever see on PC and that's the hardware decompression assist. However, considering that Sony recommends just a 5.5 GB/s NVME drive for the external expansion, it would appear that this is available for use with NVME drives as well. IE - it's not specifically part of the internal SSD as it appears it can be used for any attached drive. Of course, considering how much more compute and CPU power performance oriented gaming PCs have, this isn't an issue as can get just as fast decompression of assets using either excess CPU or excess compute resources if needed. I'm going to assume that DirectStorage will take care of those details of how to allocate system resources for such a task.