That's laughable at best. Here's a test. Ask a human being, perhaps a friend of yours, to do your next search on Google. You then do the very same search yourself. Select the results you like best, then show each other. I guarantee that you will prefer your results. In fact, his results might even be terrible.
Have you ever tried to convey your search intent over the phone to someone sitting at a computer? A real, live human being? It is so incredibly frustrating because the person on the other end of the phone doesn't know every little detail that you'd be looking for or using to qualify a given result. Most human beings 'suck' at the Internet, and even the ones who are capable of efficiently using a search engine can't possibly know every last drop of your search intent because it's not something that we convey with words or search. We can scan results so fast and process so much more information looking at results ourselves. Things like Siri would be equivalent to exlcusively using I'm Feeling Lucky.
Here's why: You know a very exact context of your search and what results will more than likely give you what you want. You know in your head things that you don't make obvious in your search. You know that even though the first results is a reuptable article, you'd rather read a result whose snippet includes the words hands-on or video rather than preview. You don't include those in your search because you ha no idea they existed 5 seconds ago, but now that you see a result snippet that mentions it, you click it. Successful searching relies on a heck of a lot more than just the initial keywords you used.
You know that a certain piece of information came out yesterday, and that any article in result dated 2 days ago couldn't possibly have the information you're looking for.
When I want to see Justin Bieber's latest music video, I want the one that doesn't look like a fan made still image video on YouTube because the original keeps getting taken down, but rather the one that's hosted on some non-YouTube site that is still active.
Siri = I'm Feeling Lucky. If human beings can't even understand your context, how will an iPhone? Searching ultimately comes down to the human being doing the search. That is why we have SERP and don't just get taken to one page or given some random piece of information. There are only so many questions that can yield exact, factual answers. The vast majority of searching is not true/false, yes/no.