I've been wanting to make a no-build webapp using Mithril.js[1][2], with plain-JS type annotations that don't require build steps (TypeScript's JSDoc syntax [3], but I'm looking forward to the proposed type annotations[4]). With something like this, type-checking would still require running a command when using Node.js, but it's just an optional developer dependency since the code would still be just standard JavaScript.
But in the end I've not done that because I figured it's more effort than it's worth, compared to just doing server-side rendering with other backend languages and just using JS where needed (not necessarily "raw" JS, I just mean it as in "not having a full-page component").
I'm just letting you know that there are definitely some people like me that would like if more JS tooling didn't require a build step or specific runtimes (like Deno or Bun) as a hard dependency.
[1]: https://github.com/MithrilJS/mithril-node-render
[2]: https://github.com/StephanHoyer/mithril-isomorphic-example/
[3]: https://www.typescriptlang.org/docs/handbook/jsdoc-supported...