Interfaces are as much a part of OOP as inheritance. Go is as OOP heavy as Java. They differ mostly in how/when an "class" is bound to an interface. Java declares up front, Go does this implicitly at usage sites aka static duck-typing (which is great!).

That said, I think OOP education focused a lot on inheritance during Java's rise and that was mostly a mistake in hindsight.

> Go seems to have much less boilerplate than Java

Maybe if you compare to Java from 10y ago. Have you ever tried to print a map in an alphabetical order of its keys?

The only thing more verbose in Java are getters/setters which hopefully will disappear once records are available.