It really depends on your App and probably the game engine. There's a reason why a lot of people use Electron for apps and it's because the amount of effort it

It really depends on your App and probably the game engine. There's a reason why a lot of people use Electron for apps and it's because the amount of effort it takes to write HTML / JS and have a functional UI is very little. It seems like you like the idea in order to implement a novel UI and I suspect then yes a game engine is a good idea. However, do consider the UX of your app. Excel is a spreadsheet because that is pretty much the best way to display tabular data. So if the novel UI isn't a better UX than an existing way you probably don't want to do it.