I believe the biggest one is sunk cost which you have already mentioned. > Among my late-stage PhD friends, it feels like 80% are unhappy The industry is much

I believe the biggest one is sunk cost which you have already mentioned. > Among my late-stage PhD friends, it feels like 80% are unhappy The industry is much better, not because it's inherently less abusive and there are still a lot of abusive employers, but because people can easily leave without too much sunk cost and go find non-abusive workplaces.