The real "complexity" that matters, as someone who has used most modern static site generators and front-end js frameworks, is in not knowing how or what broke, and how to fix it, when inevitably something breaks. E.g: with jekyll if you develop or modify content on a windows box, test locally, and then push to GH Pages, but Pages builds the site using unix, and some ruby gem or jekyll plugin doesn't work consistently across them, and it takes a good bit of experience and googling around the errors to find a fix or a workaround.
If you essentially made your own static site generator, at least you would know what went wrong and come up with the straightest line to the resolution (even if that's just modifying the build output by hand in an extreme case).
If we compare like with like and assume that in both cases you're developing locally on windows and running on GH Pages, something established like Jekyll has a much better chance of working consistently on those different OSes than a hand-written script, IME.
Yeah, absolutely. But we're talking about optimizing for complexity ("do I understand this?") rather than compatibility/features/functionality/security/community support/any of the other things you get from using established frameworks.
I'm not defending the decision, but I have worked with several folks who have this approach to using their own tools — and at times I lean in this direction too, until I have encountered breakages more often than I care to "understand them" by using my own tools — and hence trying to dissect the motivations behind that choice.
The real "complexity" that matters, as someone who has used most modern static site generators and front-end js frameworks, is in not knowing how or what broke, and how to fix it, when inevitably something breaks. E.g: with jekyll if you develop or modify content on a windows box, test locally, and then push to GH Pages, but Pages builds the site using unix, and some ruby gem or jekyll plugin doesn't work consistently across them, and it takes a good bit of experience and googling around the errors to find a fix or a workaround.
If you essentially made your own static site generator, at least you would know what went wrong and come up with the straightest line to the resolution (even if that's just modifying the build output by hand in an extreme case).