> Those layers of proper abstraction is what's largely missing currently. Or rather, is merely vaguely approximated.

This I can agree with, and my perspective would be that we have theoretical solutions with no ergonomics, and rely on unproven (as in formally proven/validated) mechanisms. WASM + capability passing is enough, but the WASM layer is still built on an OS or runtime that is not proven and you'll have a heck of a time trying to build a product on it