Hugo (https://gohugo.io) maybe? I tried it for a small static site about internal documentation, and I'm very glad I did. The hardest part was reading the documentation, the installation, content generation and rebuilds were painless.
Much of the interesting and useful tooling today is in the JavaScript ecosystem, that you will still have a package.json, Node dependency, etc. Except they are not Hugo’s problem, they arrived via a theme you are using, and they are your problem.
Hugo itself is a pretty lean template system. That means it doesn't know much about building websites. All kinds of things you hope it will know about (SEO, how to plugin analytics systems, much much more), are sitting over in themes in the ecosystem… tangled up with the axis of what visual appearance you want.
So the notion of swapping themes to swap appearance doesn't work, because the theme you picked provides a bunch of functionality in addition to appearance, and a different one will not have the same functionality.
This isn't a complaint, it is a good piece of work with many well-thought-out ideas. But it is pretty far from what the poster was looking for.
After spending a little time understanding Go templating it is really beautiful
Instead we spent a week researching how popular 3rd party themes did things, and made a hybrid. Then we moved away completely. I really wanted it to work for us and we were so close. Hugo is so fast and is brilliant on a couple of things.... but barely missed.
I can't remember exactly but with what we were doing we were going to be heavily dependant on their Scratchpad, which felt like a hack. It's all just hacks, and they like it. Lack of solid conventions, and they LOVE it.
My theme is so simple I think redoing it as themeless may be better
It's that theming structure that was a pain to figure out the first time for me
Also figuring out the variable structure took me a bit, but now the docs make sense to me.
My theme is super simple. A few templates, 1 CSS file, and a tiny amount of vanilla JS. I just let Hugo + CSS do most of the lifting.
I think some folks have had bad experiences with themes that layer a JS framework on Hugo, though. That may be a better case for a completely JS ecosystem.
There’s a lot of good options. That’s a good problem to have. Just use what you like, I guess.