Out of the use cases you mention only server-side and browser are a good fit for JavaScript, and Python does quite well on the backend. Writing mobile apps with

Out of the use cases you mention only server-side and browser are a good fit for JavaScript, and Python does quite well on the backend. Writing mobile apps with JS is a frustrating experience at best, and requiring Node for a CLI app is not great UX, unless you bundle Node in an executable. Students should learn early to use the right tool for the job, not reuse the same one just because it's already familiar. IMO Python is a better first language because it's more approachable, and doesn't have the prototypal inheritance and other quirks unique to JS (not that it doesn't have quirks of its own, but most aren't important early on).