because all that is is no more than 50 lines of code. it's so easy that nothing else makes much more sense. Go's standard library has all you need to run networking services from the get go. you really do not need these things. Go with nginx, haproxy and similar things if you need every last bit of performance, but otherwise, you can just write your on in no time. Not only that, you can tailor-made it to suit whatever use case you have and that knowledge will only make you more productive in the future.