Isn't item (3) more of a policy thing rather than a language thing? Granted, I actually never coded in Kotlin (and very very little in Go), so if it's "encouraged" in Kotlin, then your point (3) makes sense.
The nice thing about Go is that its simplicity permeates the entire ecosystem.
I'm a beginner though, and kotlin was the first language where it occurred to me I could just read the source of a library.