Exactly. I found myself so frustrated when learning Go and digging into the "gotchas" of goroutines. There is so much non-obvious complexity that could be completely avoided by providing generics so that someone else can develop a package to handle the issues for you.
you know what's hard to read? hand-rolled for loops & select blocks combined to wrangle concurrency.
the no1 benefit of parametric polymorphism in Go is going to be abstracting over concurrency