Ultimately you can, but your JSX code becomes more difficult to read and write.

> you can write cleaner code by separating your logic/UI

That's precisely the point of using a templating language: separation of concerns.

JSX mixes producing markup with your component logic.

> This look more like a rant overall.

There is a difference between an opinion and a rant. I really won't debate whether Vue is superior to React, I'm just stating why I prefer it.