It depends on how you define "need". Golang could be replaced with a notation for NAND gates and still be able to "do" everything it does now.

Yesterday I was in a pairing interview where I debugged and sped up some code. All-in-all I wound up with about 200 lines or so of Golang, including a lot of "yes, another loop" code. All I was doing, really, was mapping, forking and joining.

Meanwhile in Java, I could have gotten most of this in about 20 lines withJava 8 Streams and .parallel(). Generics make that tractable.