Spock is also a DSL disaster that's trying to be ScalaTest (https://www.scalatest.org/user_guide/property_based_testing) but in a dynamic language. Every time I use it I have to re-learn the syntax. (I have the same issue with Gradle, so maybe it's just-me?)
A "DSL" like SQL that you use hundreds of times a year you'll learn the model of.
A DSL like groovy that you use once for project setup (and for that you'll one-off it likely and stackoverflow the rest of the question) is not. And it isn't really natural, it's a bunch of arcane steps that at the end might superficially look a bit consistent, but still really isn't.
Groovy really needs an autocompleter or a generator. Or, well, as you say, you stackoverflow for everything outside the very vanilla basics of it.
But good luck getting the right version match to the syntax you need. Christ.
I get gradle is a disaster (but that's more of a poorly managed and evolved DSL problem)
But ... does anyone use Spock and think "groovy sucks"? Yeah, I doubt it.