Most of the time, the only thing we get for hard work is more work. This is not to say that we shouldn't improve things in our jobs or remove inefficiencies - this is just to say each individual should learn to draw the line somewhere and should be comfortable with that line.

"Hey I did extra at my job, but nobody cared. That's okay, no big deal" <-- this is good for one's mental state.

"Hey I did extra work at my job and improved process/saved money. Nobody cared, this sucks, my career is crap, my life sucks..." <-- time to either do less at the job or find a better job