That's what we call "the perfect job." It pays the bills, but leaves you the maximum amount of (mental|emotional|psychological|spiritual|whatever) energy to work on the things that really interest you ... outside of work.
Of course different people will approach this differently, but I don't want my job to be interesting. I don't draw any sense of self-worth / self-satisfaction / joy-in-life / etc. from my job. My job is just a means to an end, where that end is to pay the rent, pay the electric bill, buy food etc. I have enough other ways to achieve those other things, and an "interesting" (and by extension, "demanding") job just gets in the way.