I think we should explain this more clearly to the original author; it’s probably true that maybe 5% work on ads but that is literally the ads system like Adwords and Adsense. The only reason those are valuable is that Google has tons of traffic and that traffic is driven by the work of the other 95% working on sub-verticals, core search, Youtube, etc.
If you take away the people working on those these services would stagnate and people will start going to another search engine and then you lose revenue.
If you take away the people working on those these services would stagnate and people will start going to another search engine and then you lose revenue.