The code can't run with only client JS. It needs a backend. ElectronJS allows running NodeJS as backend.

I tried React Native (only support JS on the client-side, need to build native modules to run some core functions for languages), Flutter (a few missing utilities, not so familiar).

I have answer why a desktop app in other comments so I won't repeat. Electron is the best fit in this situation.

I don’t necessarily disagree with you on that point.