You can do the 20% that gets the 80% of the results, though, and still ship. I’d consider that “finishing”. Whereas a lot of devs get distracted even before that point and don’t ship.
Let's put it this way. If Christopher Columbus was looking for the new world and he got 80% of the results the reward would be a watery grave.
The other 80% of the work was sailing around the southern end of South America, and building the Panama Canal so you could actually reach Asia by sailing west from Europe.
I'm looking for the opposite of a person who leaves a trail of proof-of-concepts behind them without actually delivering anything real people can use.