Instead of adopting JSX, I would really like the syntax for this to be more like the way Kotlin uses receivers and builders to provide a generalized syntax for DSLs that happens to be good for describing component hierarchies. It would be broadly useful far beyond just HTML templating, it would also be great for expressing configurations and all kinds of other things.

The actual semantics for templating and data binding could just be a set of standard functions that use those syntactic feature, much like what you see in Jetpack Compose.