I've worked on SSD firmware before. Obvious the implementations may vary but typically there is no hard failure. These are just projections based on data sheet

I've worked on SSD firmware before. Obvious the implementations may vary but typically there is no hard failure. These are just projections based on data sheet endurance specs. What you need to look at additionally is how many defect blocks there are (another SMART spec) as it will start to rapidly increase as more and more flash blocks go bad. When the level is low, capacity shouldn't decrease as there are spare blocks. There should be no data loss expect by catastropic block failurs (some SSD have internal RAID like redundancy.) There might be a slight performance decrease as the error correction algorithms become more active.