Electron

Go down a little further in the article, it says:

Ultimately we made the painful decision to stop work on the SwiftUI Mac app and focus our SwiftUI efforts on iOS, allowing the Electron app to cover all of our supported Mac operating systems. We could have started over with AppKit as the UI toolkit for our Mac app, but this would have put us significantly behind schedule and also would have added another frontend toolkit to maintain over the long term. This decision came with a big challenge, however, as we knew we still needed to deliver a top-tier user experience on macOS.