> Without the helpful abstraction of files and folders, all we'd have are bytes stored at various addresses or sectors of the hardware.
I agree with most everything else you said, but would slightly push back on that. I actually quite like the idea of non-hierarchical blob storage searchable via arbitrary indexed metadata, as well as the idea of content-addressable storage (e.g. with magnet links). While folders are an elegant abstraction, I really feel that we shouldn't be beholden to it.
Either way - the OS is, if anything, the thing that provides the file/metadata abstraction. It doesn't exist to hide it from you.
Without an OS, you've got a CPU and memory-mapped hardware devices. You certainly don't have files.