Maven actually simplifies a lot and luckily has been kind of the standard on Java for the last few years.
For simple projects, as long as you have a working jvm and mvn on the path it is just a matter of mvn build. Also IDEs, at least IntelliJ and NetBeans tends to understand pom natively.
For more complicated projects my gut feeling is they would have been even more complicated without maven.
Say I want to use protobufs. There are a couple prerequisites: 1) I have to know the protobuf syntax. 2) I have to know how to compile the protobuf file into my language of choice.
If you're using maven, you also have to know which plugin to use (a simple google search), and add the 30 lines of XML to your build file. This is not such a big deal, except you're also hoping that the plugin supports all the protoc features that you may need. And what versions of protoc does the plugin work with? And is the plugin well documented?
Compare this to using make, or even using the <exec> ant task. protoc is well documented and you can access all the features you want in a standard way (command line options and arguments).
Last I checked when I use make I still have to find and download all dependencies before I can get a working build.
Maven sorts all that.
Maven just automates the process.
But if I had, I'm sure that manual resolution wouldn't have been any easier or more maintainable.
It feels like half the time I download a Java/Maven project, there is some issue with the build that I have to spend time debugging. I'm not familiar with Maven, and Maven is pretty complicated, so this is a pain.