Probably because people don't do this at scale. Fermi and Kepler also used laser cuts near the die to disable cores, some people enabled them with a bit of sold

Probably because people don't do this at scale. Fermi and Kepler also used laser cuts near the die to disable cores, some people enabled them with a bit of soldering (not always successful because the cores are often actually non-functional). Not sure about newer ones. Maxwell cards could also be upgraded from 4-6GB to 8GB. This has actually been a cool mod for a long time, earliest I can remember are the ATi Radeon 9x00 and nVidia GeForce 4 Ti cards, people used to double the RAM for fun and profit.