> why host other languages
Here's an example:
I recently finished building https://subzo.com.au which allows customizing and ordering 3D models. The way the model's cost, volume and other attributes are calculated needs to be done both on the frontend (for speed) and on the backend (to validate). Backend is in Go and we can't practically run Go in the browser. So instead, I wrote the calculation snippets in JavaScript (which runs natively in the browser) and ran them on the backend on a JavaScript VM library written in Go [1].