First, I’d like to ask you why you think it’s important to establish a neat dichotomy like this in the first place. Surely, in reality, there are some situations where following through is most important, and some where cutting your losses is the smarter move.
But you seem preoccupied with finding the One True Ring of what to do in life. I’m here to tell you some bad news: there is no one way. What’s good for you, might not be good for me, and vice versa, and that’s ok.
What does success mean to you? Is it making a lot of money? Is it working at something you’re passionate about? Is it both of these things?