Let’s take a look at making a film in a very simple way.
We can reduce a film into three items.
1) A script
3) A hunger from the audience.
If these three align you can get a film made. So why do you need to develop a library? Your script is a constant while the other two are not. Your script will not align with all the possible combinations. So the more scripts there are in your library the more options and possibilities you have. If you have two scripts you have two chances (or more) that will align with the other options.
Writing more scripts makes you a better writer. If you only have one script keep writing till you have a library.
I know this isn’t a question. I hope it helps.