I wouldn't say it's just a step above electron, I think the term "native" has always been a little overloaded in this way. For example, a game that uses egui for the HuD/menus could be rightly called native compared to a web game.

You're talking about "native controls", which is more specific. That said, I don't see any reason why egui would be used over native controls for this type of app. They probably just didn't think to ask their AI.

I imagine with AI, something like libui-ng would be pretty easy to improve and maintain. Looks like development has stalled though.