As someone who has built a C++ library to share across iOS and Android I completely agree. The biggest issue for us was finding developers willing to learn and

As someone who has built a C++ library to share across iOS and Android I completely agree. The biggest issue for us was finding developers willing to learn and adopt C++. For our use case we weren’t writing UI or user flow logic, it was an ‘engine’ that handled complex business logic. It used JSON as input and output. If I were to do that same project again I would use mostly native code and write our engine in Javascript.