They don't have to reinvent electron. They shouldn't need to use a whole virtualized operating system to call their web API with a fancy UI.

Projects with much smaller budget than Atrophic has achieved much better x-plat UI without relying on electron [1]. There are more sensible options like Qt and whatnot for rendering UIs.

You can even engineer your app to have a single core with all the business logic as a single shared library. Then write UI wrappers using SwiftUI, GTK, and whatever microsoft feels like putting out as current UI library (I think currently it's WinUI2) consuming the core to do the interesting bits.

Heck there are people whom built gui toolkits from scratch to support their own needs [2].

[1] - https://musescore.org/en [2] - https://www.gpui.rs

They have the resources to make native UI for all six major platforms without any AI assistance at all.

Maybe their dog food isn't as tasty as they want you to believe.

There's other ways to make cross platforms apps than to build them on top of a web browser

You are unfamiliar with native toolkits?

Bun exists and building a ui on too of that should be well within the power of the money they have. No one is saying to rebuild the universe but the current state is embarrassing.