> Many of the difficulties we encountered were due to the hybrid model approach we took
They had about 220 screens in RN, 880 native screens total. They found it difficult to juggle that, essentially developing 3 platforms instead of 2.
Personally I prefer to do pure RN, with native extensions. Not a lot of native screens, because yes, you then are developing your targets plus RN.
Also keep in mind they were early adopters and they probably had to do a lot of heavy lifting. RN has matured a lot since then, both thanks to Airbnb and to the rest of the community.