Your math is a little out there.
It's a 2TB drive and the endurance is 1200TB, so you can erase the drive at best 600 times before you have reached the endurance level. However taking write amplification into account, even at 1.2 would put it at more like 500 erase cycles.
There is a tremendous amount of grey around this issue, but the testing methodology is kind of off too (the JEDEC testing standard for CONSUMER SSD's). From memory it's something like when the writes are 10 degrees celsius hotter than the storage temperature (40 working/30 storage), how many times you can erase the drive before 3% of the drives lose data after 1 year.
So, what that means to consumers, if you are near the write endurance, what the endurance is telling you is that if you store the drive at 30 degrees for a year there should be about a 3% chance that it will lose data. Most consumers would probably go ??? to that.
Looked into this a bit more. This seems to be one of the testing methods, seems like they also test under hotter conditions and other forms of stress tests. I would find it quite disturbing if the only test they conducted was a "normal" temperature test before approving devices
Who knows what tests Samsung runs. That's where the greyness comes in, as far as I could find SSD manufacturers were not obligated to test to the JEDEC standard, and they only HAD to test to that standard if they specifically made a claim in their literature that they DID test to that standard. If they didn't test to that standard, I don't know of any other mainstream ones, so what do they test to, the answer is whatever they want...
Samsung generally make a quality product, they have had some really crap firmware on some models that have given issues, but in general if the firmware is good the drives are reliable. The point was more that the endurance rating is probably something very different than most people expect, unless they've read up on how companies arrive at those figures.
Edit: Actually, I did know that Samsung is one of the manufacturers that does test to the JEDEC standard, and their datasheet for this model says as much "documented endurance test results are in compliance with JESD218 Standards.". Lots don't though, and it really blurs things if you're comparing one manufacturer to another.
