In my years of programming Java and more recently Scala, I've never used Ant, Maven, Gradle or any of those build tools for Java. Everywhere I've worked there was a build manager who took care of all of that -- I'd compile locally with the IDE for development and unit testing, then check in the source code and notify the build manager who did what was necessary to compile everybody's files for the shared environment.

Now that I'm between contracts I've been working on my own self-funded project and it's getting to the point where it could be good enough to actually make money. I even have a potential investor lined up and plan to show them a beta version in the next few weeks.

But all along I just click the build button on the IDE, and it creates the Jar file and it works just fine. Of course, the conventional wisdom suggests that I "should" be writing my own Ant/Maven/Gradle scripts and using that instead of the IDE, but what are the concrete advantages of that in my situation (working alone)?

I've done some reading about how to use those build tools, and it just looks like I'd be writing hundreds of lines of XML (or Groovy or whatever) to do to what the IDE does in one click (the IDE-generated Ant XML for the project is over 700 lines). It just looks error-prone and time-consuming and unnecessary for my situation. Not to mention the learning curve, which would take away time from all the other work I'm doing to get the product ready to show people.