You may read the story of Sisyphus in the following link:
https://en.m.wikipedia.org/wiki/Sisyphus
(Wikipidea)Through the classical influence on modern culture, tasks that are both laborious and futile are therefore described as Sisyphean
The above quote mentions about useless tasks that will only give the doer some fatigue. I think all of you have heard of people complaining of having to do useless tiresome work.
But this book suggests that the issue does not lie with the work, but with the doer him/herself; with the way that he/she thinks; an issue of lacking inner peace.
(Page 133 - Kindle Version)The discontent are like Sisyphus if he believes that happiness and contentment can only be found on the unreachable top of the mountain, the imaginary end of the rainbow.
(Page 134 - Kindle Version)If Sisyphus has inner peace and therefore enjoys rolling the ball up and down the hill as a sort of game, then he is in a heaven not a hell.
There is nothing called 'Sisyphean work', it is just the way you think. If you have inner peace, everything will be just peaceful despite the content. Do you agree?