I would say their goal to sort and organize the world's data is right in line with their existence as an AI company. You're not wrong at all that they make tons of money in ads, but then that is also significantly understating the role of communication and Google's role in communication these days.

But the big data is essentially just the knowledge base for the AI.

Yeah, but Google did a huge marketing push that they're an "AI company" recently because that sounds a lot more scifi than the reality that Google's primary revenue stream isn't that different from a company that does cold calls. Marketing isn't exactly appealing to consumers. ;)