strictly speaking there is a simple build process on the server since plainweb uses node + tsx (the esbuild wrapper, not the markup) instead of something like bun or deno that supports typescript natively.
plainweb avoids build processes that bundle js that runs in the browser.
If Node is your backend then JS is what you need to use. Whether directly or via Typescript.
JS is just the language. Avoiding JS on the front end is more about avoiding front end code, state management, mutations, a11y issues, frameworks etc. rather than the JS language itself!
It also means avoiding using available tools in a well tested OS that is a browser like service workers, WebRTC, etc. Not knowing how to use them efficiently isn't a feature.
It is a developer time tradeoff. If your app is mainly forms and not that interactive a framework like this would be OK. Internal crud tools would be an example. But you can’t use it for everything (you can’t use any framework for everything!)
