There are quite a bit more complicated issues that require handling than just the erase count for each erase block. One part is that there are many things that

There are quite a bit more complicated issues that require handling than just the erase count for each erase block. One part is that there are many things that the SSD controller does and keeps track of in order to increase the endurance to the maximum, things like: 1. How many bits of error did we detect in the read? Maybe it's time to relocate the data before it dies completely? 2. How long does the write takes? Maybe it is time to retire this block because it is near dead for unknown reasons? 3. How many times was this block read? Maybe it is time to relocate it before we risk read-disturb issues? 4. Try to distribute data evenly across the flash dies? 5. Ensure we have enough erased blocks to write into to avoid blocking new writes. 6. Can I do some background operation? I really need to garbage collect and rescue some nearly lost data. What you suggest (and I entertained for a while too) is to return to the pre-IDE (RLL/MFM) days where the OS would do all the hard work and get all the flexibility. But the OS vendors do not want that complexity, with the more advanced technologies involved it is hard work and more importantly, it varies between vendors and for flash it can even need tuning for different flash generations or even batches. The OSes don't want that complexity. On the other side, the different SSD vendors want to use the lowest flash chips and get maximum revenue. The algorithms that they implement are their trade secrets and the thing that makes them able to charge more for the better devices. If they were reduced to a flash dealer they would find themselves getting less money. I do think that having a nearly raw flash interface and having a better processor above with possibly better algorithms would yield better results (especially if you integrate it deeper into the user application) but the complexity gets that much higher as well for the entire app and when (not if) there will be another technology the entire app will need to be rewritten which sucks.