At least 60 years ago (and possibly still today) some awards converted time and a half overtime into double time after 3 hours had elapsed.
I worked under such an award and could never understand the problems the foreman had in getting anyone to work beyond three hours. The reason for refusal was always the same – too much tax!
In those days I didn’t think these blokes got A grades in arithmetic at school, but that’s a disease that afflicts large numbers of workers in all sorts of industries.
It also afflicts pensioners but in that case the reluctance to earn taxable income is fueled by the horrors of losing a smaller amount of non-taxable government grants.