I'll be frank: you do not understand what makes Siri important or useful. It's not simple voice recognition and dictation (which Google does better), but the fact that it's tightly integrated with many apps and services. Being able to look up facts on Wolfram Alpha, set reminders and alarms, find restaurants, and countless other things from any screen is invaluable. I'd even go so far as to call it revolutionary.
Google is not even close to matching this level of tight integration (party because they don't have the same level of control over their own ecosystem as Apple does over iOS).