No project is going to exactly match every hope you have for it.
And even before you ship the work, you’ve already succeeded. No project is totally worthless.
So, given that failure and success are on a spectrum, at least partly out of our control, the real question is:
Now that you’ve signed up for this window of time and effort, how will you spend it?
We can’t possibly control the future, but we can certainly focus on right here and right now. Any effort we spend on controlling the uncontrollable bits is wasted.