NVMe is about as simple an interface to a block device as it gets: read blocks, write blocks, and a few health/diagnostic commands. Commands and geometries that originate in spinning disks have been completely extricated.
I'm not sure that I'd want the protocol to get involved in the intricacies of backing store housekeeping as you propose. Newer generations of SSDs may not even have erase blocks or translation layers; do we want to have yet another protocol when the technology changes?
But these details do matter when you want to achieve maximum performance and they also matter when you want to figure out what went wrong with the device when it fails.
The hiding the happens currently in the block interfaces (HDD, SSD & NVMe) definitely allow for easy integration and let things work pretty good for most cases but prevent getting full performance from the device and also obstruct diagnostics when things fail.
I'm not sure that I'd want the protocol to get involved in the intricacies of backing store housekeeping as you propose. Newer generations of SSDs may not even have erase blocks or translation layers; do we want to have yet another protocol when the technology changes?