There are some use cases where this really won't work. For example, if you're doing something like server-side rendering with React, and then try to "rehydrate" on the client-side, the server-side node version may format slightly differently and cause sudden updates to your UI.

Also, I don't believe you can rely on a browser having a particular locale available. I'm not sure how reliable time zone data will be either, if you need to show something in a different time zone.

I think for some general use-cases this will work well. But there's still a lot of weird issues around this stuff in the browser.