I would be an order of magnitude happier if I could work on my own projects instead of working for someone else. There's a reason people do side-hustles and punish themselves trying to get something going outside of their normal $100k salary... it's for the hope of having true financial freedom. The study is correct that $100k vs $150k doesn't make much difference at all... but if I had $1 million in a bank it would be a huge difference.

Socialists were the first and the main critics of Wage Slavery. More recently, you have the Situationist movement, which coined the slogan "Ne Travaillez Jamais!" (Never Work!) and has a body of work criticizing this model (both in capitalist and in marxist-leninist countries).

Anyone saying you "only need 105k" is not a socialist.

Oh, and the better kicker: I was even happier in grad school when I was earning $24k/year. One of the happiest times of my life. That doesn't apply to everyone's grad school experience, but for me, it was awesome. Lived in a shitty apartment above central square in one of the more expensive regions of the country (hi, Cambridge, still love you but glad I don't have to deal with your housing market). My roommates and officemates at work have become life-long friends.

I will indeed tell you that having 2M in the bank has been a much smaller factor in my happiness than almost anything else, particularly the effect of the people in my life. My day-to-day happiness is much more affected by whether I got a good night's sleep, whether my children are healthy, whether my wife and I are communicating well, whether I'm healthy and able to do the things I like or whether I've once again managed to injure myself pretending I'm 24 instead of 42. :-)

(I'm not unsympathetic to the desire for FI, btw -- quite the opposite. But I've noticed that I want it primarily in a theoretical way, for the comfort in knowing I could quit, not because I actually want to quit. Yes, I'm lucky that I have .. multiple .. jobs that I absolutely love, but I've also chosen to accept a 66% paycut to work in a job I love instead of blasting to FI in industry, and I'm good with that. Sometimes it annoys me and I go do some consulting or bitcoin mining to help make up the difference. :-)