> Two-way binding is a step back I think

You don't have to use it – its effects are restricted to the subtree where you've explicitly opted in to it. I've personally found it to be a huge timesaver, and would never go back to a world where I didn't have the option of using it. But you're in no way forced into it.

> I wonder if these ideas can be somehow applied to React

A lot of people have wondered that, including me. Unfortunately, a compiler wouldn't be able to generate a good picture of the structure of a JSX component – because it's 'just JS' it resists the kind of meaningful static analysis that Svelte can take advantage of. I'd love to be proven wrong, but sadly I just don't think any JSX-based framework will ever be able to fully embrace these techniques.