It could just come down to different binning of the same part, and it would still make a difference.
The why I’m still talking is because people seem to think buying a gaming SSD is a good idea when they also want longevity / low risk of future. The parts can last 10+ years but they’re designed with something else in mind.
One hardware guy mentioned internal defects can cause differences is the amount of reserve sectors that a final product ends up with. That’s exactly the kind of arbitrary cutoff that lets companies charge different prices for the same part.
Lower-grade flash with higher initial defect rates is what gets used in USB flash drives and SD cards, and some bargain-bin SSDs with lower usable capacities (ie. 960GB rather than 1TB).
The stuff used in a WD Black or WD Blue branded consumer SSD is not a different quality grade from the stuff used in any other mainstream consumer SSD, Apple's included.
Hell WD chips could be of higher quality as I am not suggesting I know their internal processes. I am saying things are optimized differently.