Yes, but Moon's goal is to have syntax similar to Vue's, and as a result, requires an HTML template compiler, Javascript expression compiler, directive compiler, and different component logic.

RE:DOM doesn't have any of these, but only has a virtual DOM engine (which Moon has as well).

Moon's benefit, that I can see, is Vue's syntax.

with the difference between sizes being a few kb, I don't think that they would entirely matter. What really does is execution rate. Which one performs more efficiently. If the end result is DOM, it doesn't matter what syntax you're using, the client is the most important part

I honestly don't see much similarity