The overwhelming majority of it? Yes.
>In this case you have a literal webapp that they also want to bundle as a desktop application. Turns out Electron is the most convenient way to do this.
That's just it, though: Developer convenience; at the expense of the user's experience and resources. So many developers digging-in their heels, refusing to use any other GUI framework because they can't be bothered to learn or use anything beyond JavaScript. If that isn't the excuse then it's because an MVP is needed and, because the market is replete with JavaScript developers, Electron was chosen as the platform on which to build. But after the project is green-lit, surely the product will be built using a more performant, lower-weight framework, right? Well, no, because that only benefits the end user.