It does have them. There are many toolkits that provide components for the web. Bootstrap is just one of them and one that has been getting a lot of publicity here for a while because it's new and has a nice design. But there are many out there that cover different aspects of mobile web development: YUI, Sencha Touch/ExtJS, Dojo, jQuery UI/Mobile, Enyo...
And pre-made toolkits still require you to tinker with them to get layouts right, make them fit your design and make ads work OK in them. That's true for both the web and native toolkits.
And pre-made toolkits still require you to tinker with them to get layouts right, make them fit your design and make ads work OK in them. That's true for both the web and native toolkits.