Comment by StillBored

Fundamentally the job of the OS is resource sharing and scheduling. All the low level device management is just a side show.

Hence why SSD's use a block layer (or in the case of NVMe key/value, hello 1964/CKD) abstraction above whatever pile of physical flash, caches, non-volatile caps/batts, etc. That abstraction holds from the lowliest SD card, to huge NVMe-OF/FC/etc smart arrays which are thin provisioning, deduplicating, replicating, snapshoting, etc. You wouldn't want this running on the main cores for performance and power efficiency reasons. Modern m.2/SATA SSD's have a handful of CPUs managing all this complexity, along with background scrubbing, error correction, etc so you would be talking fully heterogeneous OS kernels knowledgeable about multiple architectures, etc.

Basically it would be insanity.

SSDs took a couple orders of magnitude off the time values of spinning rust/arrays, but many of the optimization points of spinning rust still apply. Pack your buffers and submit large contiguous read/write accesses, queue a lot of commands in parallel, etc.

So, the fundamental abstraction still holds true.

And this is true for most other parts of the computer as well. Just talking to a keyboard involves multiple microcontrollers, scheduling the USB bus, packet switching, and serializing/deserializing the USB packets, etc. This is also why every modern CPU has a mgmt CPU that bootstraps and manages it power/voltage/clock/thermals.

So, hardware abstractions are just as useful as software abstractions like huge process address spaces, file IO, etc.