I don’t work at AirBnb but I would honestly be shocked if they didn’t use some sort of flux architecture (it might not be Redux per se but some other one).
I’ll give you a very simplified example with Spoil. We load up products, contacts and a user profile. On the home page we greet you with a “Hello Voon!”
With Redux I am easily able to fill up my state with a user, and then using the Redux store I am able to access that user from anywhere.
If I didn’t use Redux, I would have to pass that value as a prop to any component that I need in the future.