It's all a matter of balance, sometimes you work in a genuinely nice place but you have shitty working hours and/or wage, you can't properly study and update yourself, no energy to workout or take care of your body or do 'useless' stuff that keep you sane (any hobby will do, rc cars, music, woodworking)... so some people find (for example) a good paying and simple/undemanding job with great hours, so they get home and can still attend uni, workout, have proper hobbies etc.
Source: worked at a place where i felt accomplished and technically challenged all day long but I had no free time, was fat as fuck, had no time for the wife etc... am now at a much lighter dayjob, managed to find time to finish uni, lost weight, have hobbies etc...
It's easier to yearn for personal satisfaction when you have all your necessities (and those of your family) secured. Changing jobs to a less-paid one is difficult, because the gains can be quickly offset by the loss of financial stability, and let me tell you, if you don't have money for your (and your family's) basic needs, then you can be really unhappy.
But yes it does suck to question oneself all the time on whether to switch it up or not