And at least the last time I used it in anger (which was, granted, perhaps double digit years ago), the docs started out with and loudly proclaimed "here's how you write your own tasks!" Wait, what? I want to have a build system do at least the 80% case with minimal/zero work; why am I jumping right in to my bespoke needs?
Not sure if this was just bad doc, or the tool actually didn't do the 80% very well then or what, but it's stuck with me.
That's mostly my experience with ruby, too: you can type anything, don't worry about it!
I wanted to mention that Gradle since I think about version 7 supports mostly static typing via Kotlin but regrettably it's lipstick on a pig since almost inevitably one needs to interact with the Groovy side of the house and then all bets are off