And for people who want "Hugo but written in Rust" or "Hugo but written in Javascript" — then, there's Zola (Rust): https://github.com/getzola/zola, and 11ty (Javascript): https://github.com/11ty/eleventy. (Or at least that's how I think about these two.)
Why would you want that? I generally prefer Rust or JavaScript over Go. But with a static site generator, you're not actually using the language at all, and Hugo has a much bigger ecosystem.