A native virtual DOM implementation would also drastically reduce memory overhead since browser engines could optimize diffing algorithms at the C++ level instead of requiring megabytes of JavaScript framework code to be downloaded, parsed and executed on every page load.
The linked proposal has many "features" that would be "needed" if you frame the problem in terms of a "template api", centered around "binding" variables, and what not.
Doesn't your proposal implicitly introduce the concept of a virtual DOM, which the browser does not have?
You'd need to spec out what that looks like. It adds one new API from the users perspective but much more from the browsers perspective.
Additionally the next generation of Frameworks do not use virtual DOM. Solid and svelte do not. Vue is moving away from it. Signals are directionally where they're all heading.
The API surface I propose only includes one function. No type needed.
It does not even require the target node to be created with a virtual dom in the first place. Just diff the node with the given tree structure efficiently.
Internally the browser might need to create a few accelerator data structures, but that's an implementation detail.
More specifically, a native implementation of the "patch" function:
Where `virtual_dom` is just a plain-data description of the DOM.Most of the "slowness" of the DOM come from its requirement to be a 90's era Java style object hierarchy.
Don't call it "templating". Just call it "virtual dom". Everyone knows what that means.