SwiftUI is an attempt to stop the spread of people coding for things like React and instead focus in a Apple only SDK so they accomplish their goals of developer lock in.

Knowing why Apple is doing this is important to understand why this will never happen.

Apparently the feature they are using is function builders (1) and its already working on the current versions of Swift. So at least now, nothing is preventing other people to try to replicate in a open source manner those features.

By the way, there are some projects on Github that already implements the same functionalities.

Don't wait for Apple to open source this kind of stuff, because one way to enforce lock in, is through API. And Apple is far away from being a benevolent big other as some people might naively assume.

1 - https://www.swiftbysundell.com/articles/the-swift-51-feature...