When HTML reaches the browser, all the markup is parsed, and the browser creates a Document Object Model (https://developer.mozilla.org/en-US/docs/Web/API/Document_Ob...). That object model is an extremely robust API that's loaded with tons of functionality, not the least of which is working with events (https://developer.mozilla.org/en-US/docs/Web/API/Document_Ob...).
The browser itself brings so much functionality that you can do stuff like check the status of the battery; create, save, and access files; get someone's precise lattitude and longitude; and _create and subscribe to streams_.
I'm not sure what you mean by, "html does not allow for event handling," ... but if HTML exists in a browser at all, there's plenty of event handling to go around.