The string of thinking goes like this: Even though I'm desperately unhappy, it's a paycheck. I might not find another job.
Then, there's sugar-coating: Anyway, we're all floating in the same boat. I guess I'm really not so bad off.
And the clincher: Besides, making a change would be a heck of a lot of work. I don't have the energy for that.
So you stay stuck, wishing for things to stay the same, but get better.