Myth: Academic work is inherently noble and meaningful.
Reality: This is true, but only if you enjoy it.
That's really all I have to say about this one, but it needs to be said.
Producing original research, setting your own (often indefinite and ongoing) work hours, and teaching future generations is a noble calling, and an honorable thing to do. It's hard, and it's frustrating, and it definitely has its own rewards.
But if you don't like it - if you don't like teaching, or writing academic research, or writing grant proposals, or having a lot of unscheduled time - well, it doesn't matter how noble or meaningful it is. You will be miserable.
And you shouldn't stay in any position, no matter how noble and meaningful, if it's making you miserable.
It's okay to leave a job. Even a noble and meaningful one.