So, Wordpress, with its very flexible schemas and tens of thousands of plugins, and total freedom to do whatever with custom php is "too limiting" but a static site generator is not? Maybe have another look?
I recently built a blogging/gallery template that I'm very happy with. My goal is to keep it JS free. I originally wanted to apply it as a theme for PHP/WordPress, since I already had an older one I could rework. But it didn't feel like the end result with JS was worth it. Hence the static site generator route. In theory I think I'll have more control for exactly what I want.