From 1971 until i retired in 2016 i worked for about 20 different companies in Uk,Holland,Canada and Sweden.Driving Europe,ME,USSR,North Africa,Canada\USA and Scandinavia.I can honestly say that in 90% of cases i left for other work[more interesting],money was a negligible factor.If the work was crap no amount of money can compensate but if the work is fun,challenging and interesting then the money comes anyway because you work better.
I suppose the most enjoyable work was ME,ships stores, Diplomatic work,winter driving in Canada and glass transport for Pilkington.