Why do we measure the value of a video game by the time it takes to complete it? Or the time it takes to actually complete it, 100%? Or by how many hours we continue to invest in a game with no true ending?
We don’t measure the value of books, shows, movies, or songs by their length. If a book outstays its welcome, we skip ahead to the ending (no cheats required). If a show takes too long to wrap up, we drop it like all those other series overextended by executive meddling. If a movie bores up, we walk out of the theater. We measure other media by their impact.
The obsession with video game length as good stems from a historical accident. It came from a time when consoles and cartridges were exceedingly expensive. Super Mario Brothers would cost $200 USD in today’s money. And developers had few options for expression, which pressured them to validate the expense however they could. Even today, $200 USD buys a lot of books. But that time has passed.
Such pressures and constraints don’t apply to you. With the Internet and modern tooling, you can create a game in an incredibly short time (if you keep your scope in check) and distribute it across the world in minutes. You can make a game last only as long as it should last, at its best length, and spend only as much time on it as you see fit. If your game will be worth playing, then your players need your game sooner rather than later. (Even if it takes a post-launch update or two.)
You don’t want your players to miss your incredible ending just because they got bored, do you?