An unfinished masterpiece still cannot perform its purpose.

Quality does not substitute for existence. Something unfinished, however good, cannot do the thing it was made to do, which means all the care in it produces no effect. The difference between excellent and unfinished is not a matter of degree.

If you are holding something back because it is not ready, ask what would happen if it went out at its current quality. Often the answer is that it would work. Purpose requires completion first.