It's a growth hack to get better organic search traffic, with user experience performance improvements a secondary concern.
When a big company like Airbnb jumps on a technology bandwagon people notice, and write-ups like this influence the choices other organisations make. They could at least just be upfront about the reasons why they're doing it.
The search benefit isn't even a long-term one: Either AMP will go away for some reason at some point, or, if the status quo is maintained, everyone will be forced to use AMP by Google's search monopoly, rendering it a null benefit to your rankings as everyone else transitions to it.
> it's very unlikely that Airbnb wants to admit they're probably being paid for it or getting some other form of special consideration for writing this.
It doesn't look like anyone from Airbnb wrote this. But you're right, that's a good strategy - instead of the accommodation and experiences thing, they should implement AMP and get paid by Google for it. That's how business works: https://i.imgur.com/Vd6gI7X.jpg?1h
Congratulations Brian and Gil on implementing this!
Maybe in the long term, but meanwhile they get the benefits for being early adopters. If AMP fails, they will simply roll back.