There are a few good packages to handle model mapping. What the article is trying to make you think about is the risk of managing the complexity in a web framework versus putting together packages that solve different problems. This is especially true with Go which is designed to be very easy to combine packages.

For example, see https://larry-price.com/blog/2015/06/25/architecture-for-a-golang-web-app/ to get an idea of how you can build you own framework by putting packages together.