Hard to believe they could get that endurance rating with the usual TLC flash. MLC, SLC?
The capacities would suggest it's MLC, not SLC. It's probably the same NAND chips modern enthusiast SSD use, but just configured all to run in pseudo-MLC mode. When you do that on NAND capable of usable endurance in QLC mode, it's probably not too surprising (TBH, I wouldn't have guessed these endurance levels would be possible outside of SLC).
Today everyone in consumer world uses TLC with max 600 TBW.
No, only enthusiast drives are TLC. Most of the consumer world is using QLC.
the Samsung 840 lasted over 2.5x past its 73TBW rating before any uncorrectable errors popped up,
Okay, so 182.5 TBW vs. 219,000 TBD? You're off by 3 orders of magnitude.
Anyway, I think you're reading too much into the 2.5x discrepancy. Part of it is that the manufacturer needs to build in some margin of error, because the endurance is going to follow something like a bell curve. They'd want to be sure that they guarantee about 2-3 sigmas less than the mean endurance.
Also, they probably allow for it to be operated at higher temperatures than TechRepublic's testing used, and that's very detrimental to endurance!
and much longer past that while still in a usable state.
I'm pretty sure it doesn't need to get
that bad, before they'll accept it for return under warranty.
So now a high endurance rating makes a drive “AI” instead of enterprise?
Last I checked, enterprise M.2 drives are pretty much extinct. I bought the last one I could find, and that was a Samsung PM9A3. The only place I could still find them for sale is ebay.