Another thing is that searching the web is steadily becoming displaced by more structured and localized forms of search, such as videos, nearby restaurants, products, used goods and so on. In some cases keyword search is replaced entirely - by recommendations & personalized simple buttons (gas stations on the way to my destination, the latest episodes of my favorite podcasts, etc etc).

From an ad-pipeline perspective, Google isn't entirely left behind in this new world, they still have YouTube, Google maps, Gmail, etc. However, they missed most of social and e-commerce, which feels irrecoverable at this point.