Look, your application is certainly impressive, but it's extremely basic from the perspective of a UI toolkit.

- It's not multi-window, so it doesn't have to integrate with a bunch of the OS window management affordances.

- It doesn't have any complicated typesetting or rich text editing, so you get to pretty much ignore that whole mess.

- Since it's a very visual tool that doesn't make much sense for blind folks, you haven't invested much in accessibility support.

- And so on...

This is a great use case for EGUI, and EGUI works great in this sort of UI-lite scenario. Whereas I wouldn't want to use it to implement something on the complexity of VSCode/Excel/FireFox.