Darknight OP.
The PS5 on board nand storage is just as likely to die just as any other on board nand storage.
Keep in mind SSDs don't have moving parts so they don't wear out over time like a magnetic disc based drive will (HDD). A SSD's longevity is determined by how many writes you do them over the lifetime of the device.
For example the primary NVMe drive in my PC is a Samsung 970 Evo Plus, which has a failure tolerance of 600 TBW (That's 600 Terabytes written) this means I'd have to write 600 terabytes roughly before the drive starts to deteriorate and fail.
I built this PC back May of 2019, so I just over a year and half now and you want to know how much data I've written to my drive so far.
7.7TB written in over a year an half of heavy use daily and it's lifespan is rated at 600TB. That's 1.2% out of its maximum potential writes and with continued use at the same rate would take 15 years to hit 77 terabytes written, let alone the drives rated longevity of 600...
The failure tolerances for SSDs are by far much much higher than typical magnetic storage / HDDs.
Folks are having bit too much
concern over a technology that has been proven reliable and existed for many years now.
By the time SSD in a PS5 dies from normal usage you would have likely moved on to a PlayStation 6 at that point. In fact the more moving mechanical parts like the consoles fan or disc drive are more likely to fail before the SSD ever will.