Right, so then it is more complex than `go build`. QED.
To be clear, I'm not claiming that Go is "better"; I'm just pointing out that this is why one would chose Go over Java. Sometimes this particular benefit doesn't outweigh the costs relative to developing in Java, but language/toolchain simplicity remains -- nonetheless -- the reason why people prefer one over the other.
Yes, "gradle build" wants to see a "build.gradle" file in the current directory, but you can run "gradle init" to get one. And after that everything except specifying dependencies is by convention.
There's really little to no difference in complexity here. What Go saves by not having a build file it loses by not encoding enough information about dependencies in the source, which leads to horrible hacks like vendoring.
So now I need to change my text editor?