React would be pretty horrible to implement in the browser. It can't use most of the DOM API: you can't set properties on element, can't add event handlers to e

React would be pretty horrible to implement in the browser. It can't use most of the DOM API: you can't set properties on element, can't add event handlers to elements, create comment nodes. And VDOM and diffing is one of the slower ways to update the DOM. We should build templating and DOM updates into the browser, but we should do better than React.