I sort of agree - for now, at least. The tooling around React for debugging is pretty great. React Dev Tools lets you easily debug your component tree. And the underlying source is pretty much what you wrote (JSX doesn't really get in the way here).

I've been working with some older Angular (1.5) code recently and it's been an absolute nightmare because the debugging experience is just awful. Error messages are unusable at times. Failures simply get swallowed. It's difficult to debug bindings. But with React, I don't have to deal with any of this (though much is because of the simpler API).

You see a similar thing with Redux. It's very straight-forward to debug, and there are similar dev tools. Even Apollo has dev tools for their GraphQL library. And I think this is what sets these things apart and makes them so much more popular than similar libraries - the debugging experience. And while I haven't used Svelte for a project, I'm getting the sense that the debugging experience is going to be painful. It may be great _most of the time_. But I don't think that's going to be enough in the long run. Just my opinion.