That's the baffling part. I would think YouTube alone would crush Facebook in profitability. Then add all the other things Google does and it's not even close.
I'm reminded of the Hastings quote about Netflix's biggest competitor being sleep. As far as the various infinite-scrolling ad-machines are concerned, the primary input is users' time, and whatever the service does or looks like is just window dressing in service to triggering dopamine hits to keep users scrolling.