The OP mentions things like Nextjs, which I find odd. A well crafted site built with the help of Nextjs (and similar) works w/o JS just fine: The site becomes progressively enhanced through hydration, but if you disable JS altogether, you can still read and navigate the site.
For sites with minimalist designs, straight forward data models and low to no interaction (like a blog or similar) I agree that any sort of JS can be overkill. But professional web devs use these technologies because they tick some important boxes (trade-offs) ranging from expressivity, structure to performance and provide a uniform way to write front-ends.
For sites with minimalist designs, straight forward data models and low to no interaction (like a blog or similar) I agree that any sort of JS can be overkill. But professional web devs use these technologies because they tick some important boxes (trade-offs) ranging from expressivity, structure to performance and provide a uniform way to write front-ends.