They're becoming Yahoo...they need insane qtr to qtr growth or else its stock gets smashed, and takes everything else with it. Who wants to work for a has-been?
Google escaped it by adding ads virtually on 100% of the page and added ads one by one on mobile pages and didn't do them much harm. How many ads are now on mobile, 4 or 5? Google still can monetize Maps and Translate and people are doing more of their stuff online.
I guess FB can add more ads but "everyone" has or had FB so adding new users is a challenge. Not sure how Whatsapp can be monetized, in a way that is worth trying.