Here is more on how they reduced the binary sizes: https://twitter.com/bradfitz/status/1256350305739915265

> Mostly https://go-review.googlesource.com/c/go/+/230544 and also https://go-review.googlesource.com/c/go/+/231397and lesser misc stuff like https://go-review.googlesource.com/c/go/+/228111