You answered your own question there. Back then, Google was primarily a search juggernaut. They didn't have many real life situations that they needed to resolv

You answered your own question there. Back then, Google was primarily a search juggernaut. They didn't have many real life situations that they needed to resolve or take care of. They didn't need to deal with any sort of insurance for their clients (like AirBnB does for their hosts), they didn't have nearly as many tricky questionable real life situations to resolve (the host cancels your housing reservation a couple of days before your have your already reserved flight, what do you do). Google was just providing search results, and almost all their work was limited to the virtual space. Pretty much a pure software company providing only virtual space services. You don't usually get a complicated real life situation to resolve every time there is an incorrect search result, almost every issue is resolved by making a simple code change. Due to the inherent nature of AirBnb, it just has magnitudes more non-purely-technical problems to deal with. And you will also need technical work to resolve them too, but it is just a small component of those. For example, how do you deal with verifying hosts? You need to build some verification mechanism, but it will almost always need a human in the loop. So not only you have to implement the technical flow for it (like a verification portal or whatever), but you also need to pay people to process all of this and resolve any issues arising. And I expect that with every heavily human-centric problem, you will need a lot of human resources to deal with it effectively. Add the fact that AirBnB has to deal with those "physical world" problems in 191 countries (all with wildly different legalities that come with short-term rentals, which is the core of their business), it doesn't seem to have such a large number of employees at all. Disclaimer: I am not saying that AirBnB is NOT overblown in terms of employment numbers. They very well could be, I cannot tell without understanding the entirety of their business. But I can definitely say that it makes perfect sense in my head that AirBnB in 2020 would need significantly more employees than Google did in 2005.