Is it possible that by building and using your own program, and most likely learning a lot about accounting in the process of making said program, that you became better at managing your money even without using the program afterwards?

On one's path through upward mobility, if you spend all your money before you get to your goal, that might prevent you from reaching it. Even for people with high salaries, they need to control their spending. For some that might be a spreadsheet or an accounting app, for others they might be fine at managing it all in their head.