CoffeeScript was not in fact just Javascript. Litestream literally is just sqlite3; it's not an app dependency, and doesn't interpose itself between your app and sqlite3. You could add it to an existing single-process SQLite-backed app without changing any code or configuration, other than running the Litestream process.
It's brilliant that a person can ship their WAL from an app that doesn't know anything about Litestream. That's cool. But it is not in fact just SQLite. If it were, there wouldn't be a blog post, or an additional binary to download, or a backup of my database in S3, or...
I think saying it is “just SQLite” is (unintentionally) misleading. Your app may not know it’s anything else but operationally it’s a sidecar, so another process to manage.
I actually had to go look that up because it was a little unclear from the blog post and this comments section.