No, not essentially the same thing. For one, many of us prefer a minimalist dock. That aside, I can easily open launchpad from wherever with gestures instead of having to navigate the cursor to the dock, first (I work on a dual screen setup, one of which is 27"... yes, it makes a difference in workflow). And I can have different pages for different types of programs that I can swipe between, for example, I can have folders, ... it's one of the things that swapped over from iOS that actually makes a lot of sense and is really great and useful.
And the spotlight alternative that some suggested and many seem to use is also not really a great alternative. I'm a visual person. I know which icons to click. I don't want to have to think about the actual apps name, nevermind that spotlight has become very cluttered.