There is still work here for me to do

I regularly question why I stay in my current job, when I could earn more outside the organisation.

I've come up with this answer:

There is still so much to do.

I got advice long ago that if you run away from something that needs fixing, then you're doomed to repeat the same failure in the next role.  Whilst I think that people can "start afresh", I do agree that one needs to get it right before moving on.