It really depends entirely on the person and their scenario.
Scenario 1:
Wife and Husband live in their small Midwest hometown where all their family is. Husband is a stay at home dad with minimal earning potential. Wife has her MBA and is a top executive at the towns only large employer in the city. They have 3 young children.
Scenario 2:
Myself and my wife. I am a contract working and as such, we move all over the country for work and have no roots anywhere. We would have zero issue leaving a job and moving across the country in the next week. I’ve had similar situations countless times. My wife doesn’t work, so it’s even easier for us. I make a lot of money, and being so mobile, we aren’t stuck in any one place.
Scenario 1: would take a LOT of money IMO opinion to say “FU.” They would likely have to leave their hometown with all their friends, family, change schools for the kids, etc., to keep the same or even a remotely close earning potential. OR, potentially take a major pay cut to work elsewhere in town because you burned bridges with the towns only major employer.
Scenario 2: it really doesn’t take that large of a stache for me. We’re at around a 70% savings rate right now, and have around 6 years of living expenses saved, with around 8 months of an emergency savings in our savings/checking. If I were to say “FU” I have no doubt that I could find a job where I’d still have at least a 50% savings rate within a month. My FU would definitely involve a several month sabbatical and then looking for work.. I’ve been very, very close to the FU a few times in my career, but when you are getting paid such an absurd amount, it’s amazing how much more you put up with. It’s a lot harder to walk away from $300k than it is from $75k. My current job I was having so many issues with my coworker I told my boss that if this guy was still employed when I moved, I was only signing a 6 month lease instead of a 12 month because I needed an option out if I get to that point I am that fed up.. My boss fired him in January and I signed my 12 month lease last week lol.