Resumability is still a kind of hydration, I suppose, but it's so much more efficient that it makes sense to separate it from hydration and just say it's "no hydration" same as some frameworks advertise "0kb js" when what they mean is just a kind of progressive enhancement that still includes js.

There is no vdom on Qwik, it is kind of a requirement for fast hydration / resumability to not have a vdom – otherwise there is only so much optimisation you can do when you need to convert all your server-rendered markup into a vdom representation.