At Airbnb, most core flows (search, home booking, map, trips/itinerary, inbox / messaging, the signup/login screen, profile, settings, and the hosting flow for listing your place) are all native. Most screens are built using a declarative abstraction on top of UICollectionView and UITableView.

The Trips tab in the app (itinerary) was actually rewritten in native after originally being implemented using RN.

It’s really too bad that people have this perception of RN’s use at Airbnb. I feel like people assume the whole thing is RN, which couldn’t be more wrong.

Yeah it's pretty easy to tell, even if they've been modified to not look like a browser frame if you notice poor performance or increased memory usage you just have a look in activity monitor or ps and you'll quickly see the javascript web workers etc...

It sounds like you're talking about electron-style desktop apps, not React Native? They're quite different in architecture and performance.