So? As long as you have same style on your project - any style, your code will be readable and with less WS conflicts. I don't see what a built in formatter does, other than allow to minimize bikeshedding about format, which will just pop up as BS about libraries or VCS or something.
That is assuming built in formatter doesn't have configurable options. Which some formatters do.
>I don't see what a built in formatter does, other than allow to minimize bikeshedding about format
That's exactly what it does -- and it's an absolute wonderful experience to see it in Go. I'd say it again: very few people don't like, and most that tried Go were singes the praises of this idea.
That strikes me as a minor quality of life issue. Great, you've removed about 1% of all Bikesheds (which library,which framework, etc). Not, something that NEEDS to exist.
That is assuming built in formatter doesn't have configurable options. Which some formatters do.