But, you're right that Gatsby requires a lot of code. To get a simple static site setup, it's a lot of work. Plus it changes very fast. We stopped paying attention for a few months, and things broke on the next upgrade.
But, if web performance is the goal, Gatsby is hard to beat. In addition to pre-fetching, it also inlines every resource, images, CSS, the whole thing. So a single HTML fetch should be enough for a full first paint. That's a lot faster than a usual static site, which in turn loads all the additional resources before it can show the site to the user.