This site inexplicably buries the "what does this do and why does it matter" explanation:

https://www.agnosticui.com/docs/understand.html#benefits

That page also notes that AgnosticUI is not ready for prime time.

Something similar. Write components once, run everywhere. Compiles to: $manyWebUILibraries

https://github.com/BuilderIO/mitosis

Thanks for sharing. This is similar to using Bootstrap for your styling, and then you have lots of component libraries across technologies that work with it.