I could be wrong here, but from what I understood the cost of maintaining a hybrid RN + fully-native apps > full-native apps. I.e. What airbnb would gain by not having to code both android/iOS was lost by having to deal with all the RN non-sense (third-party libraries being deprecated, very fast non-backward compatible changes, etc.) but also having to always bridge the gap between what was RN and what was truly-native. At the end of the day, you look at your time and you realize that you spend more time trying to make it work with RN to "save time" rather than just coding it on both platform.
But then, most people using RN don't have to deal with this issue because they don't have an existing non-RN code base to bridge with RN.