Together with wasm / js this can give you super lightweight 'electron-like' standalone apps in less than 2 MB. Used as such in in https://github.com/pannous/wasp/
Web servers aren't big! Browsers are huge but servers can be tiny.
I'm sure Caddy and nginx and the like are at least 2MB, but they have a lot of features. Googling around a bit for small web servers, I found this fun blog post: https://lipanski.com/posts/smallest-docker-image-static-webs... They ended up with a static web server in a 154KB Docker image.