Stress
Remember how we established that the audio engineer rarely gets the credit? Well, guess who gets blamed if something goes wrong? Yep, the engineer. If there was ever a job that demanded perfection, it's this one.
Studio engineers work very hard not only to eliminate interference and other unwanted noises from tracks, but to make sure each musical note is rich with harmonics, and that each track is mixed to the right volume and quality.
Live sound engineers work hard to keep those squeaks and pops from happening...but they still happen occasionally, with dire repercussions. The sound guy struggle is very real. The flip side is that sound engineers tend to have highly flexible schedules, and generally enjoy their work.
With decent pay grades, plenty of room for advancement, and challenging yet rewarding work, most audio engineers aren't complaining.