AI is vaporware. Hawking opinion on it is worthless... as is Musk's (I love how Musk was nominated for The Luddite Award for his tirade on "the AI apocalypse").
Computers really haven't changed that much in 20 years. They still do the same crap they did 20 years ago, only faster. Humans literally have no idea how to create artificial sentience, and frankly that's a good thing. We are an irrational and destructive species that have nothing of value to add to the universe. Lets be honest about it.