I've actually written a couple of my own JS SSGs in the past 10 years. My first one started off as a couple of scripts strung together with Gulp, then moving to Wintersmith, then another of one the x-smith ones. Never doing that again.
Re-writing my current blog in Astro. [0]
Yes, it is more complex but that also means it has more features, features that I don't have to code or maintain myself. Simple features like rendering markdown to html. Or syntax highlighting. Or figuring out which markdown files to render where.
[0]: https://senhongo.com/blog/rebuilding-this-blog-in-astro
It's nice to read someone else's take on writing an SSG. I wrote one [0] specifically to generate a microblog [1] so I use a single markdown file with additional directives to provide meta data like tags and to split the file in blog entries. I am considering writing an SSG that can handle a large blog so I bookmarked your site for inspiration; thanks! I probably am going to use Python for it, though.
[0] https://github.com/john-bokma/tumblelog [1] https://plurrrr.com/