Building software is not easy if you don’t know the key flows that lead to providing real value to the users.
There are many ways to master those flows, and the most enlightening one only happens when you are a user of your own software.
Building software you’re going to use is key to providing a great value.
The only catch is that sometimes “scratch your own itch” apps are so focused to a super-tiny niche that no one uses them except the creator. Key is having a bigger vision for the app, and keep it more general that you’d want, so it will be useful to others too.
Using yourself the apps you build is one of the best ways I know of ensuring them a long life of nice updates and usefulness for the years to come.