I'm not sure what you're talking about, but DOM rendering systems aren't really part of the web components suite of standards right now. That's left to userland

I'm not sure what you're talking about, but DOM rendering systems aren't really part of the web components suite of standards right now. That's left to userland and there are a few web components libraries that do use VDOM for rendering. Now, as a Lit maintainer I do think that VDOM is a lot of unnecessary overhead, and the benchmarks show that, but rendering libraries and web components are orthogonal things.