Using CSS to select elements within the browser arguably only became popular because of jQuery, (and Prototype, Mojo, etc.). The browser inbuilt suggestion at t

Using CSS to select elements within the browser arguably only became popular because of jQuery, (and Prototype, Mojo, etc.). The browser inbuilt suggestion at the time was to programmatically navigate the DOM, or maybe use XPath. Proposing CSS selectors as a browser API before it became dominant in the wild via alternatives would have got a "why do we need another option?" response.