- It's easier for you, the savvy developer who groks the toolchain, because it allows structure and reduces repetition.
- It may very well be easier for the next person who wants to add a page or change some copy, because editing Markdown and running a couple (admittedly esoteric) commands is likely still easier than editing HTML directly.
- If the next person doesn't understand or like the toolchain, they can ignore it entirely and edit the HTML directly, which is no worse than if you didn't use a generator at all.
So yeah, you don't have to use tools, and yeah, CMS sites and compile-to-CSS is probably overused in the small-site market, but I think static-site-from-Markdown with vanilla CSS is a pretty sweet spot for this!