No I was saying the opposite, a static site is necessarily not dynamic.
I would not want to pre-generate those pages. Your static files on an S3 bucket are still served by a webserver.
Anyway, can you honestly say, hand over heart, that server side rendered JSX or React is a robust and simple solution comparable to SSI or I don't know, a bit of copy pasting? Of course not. Server side rendering is a complex toolchain that will rapidly and constantly deprecate. My blog has been sitting on the same "stack" for 13 years, takes me 5 seconds to set up a new post.
I have worked on countless JS projects, sometimes they don't even build just 6 months later without faffing about with packages and versions.