Outside of US the Uber brand is not so strong. In EU they are very regulated and they compete with local players that understand the market. Asia is also dominated by local players. So Uber exists in these markets, but almost nobody uses it there.
Only Xamarin.Forms introduces another layer for you (it is the same concept as React Native). If you use Xamarin.iOS and Xamarin.Android you call underlying APIs directly. Although there can be issues with bindings, nothing like you will face with React Native.
I am aware of why C# isn't popular among startups. It is sad because C# is a great language that has amazing tooling support. It runs everywhere - Xamarin for apps, ASP.NET for servers, Blazor for browsers, and it is getting only better, and I cannot imagine how awesome it would be if other companies helped Microsoft. But I can only dream.
It includes a bank account that is huge money and time saving for people outside of US. If you do it elsewhere you will have to fly to the US and open the account yourself.
This isn't true. Copy-on-write semantics are implemented only for arrays, dictionaries, and strings. Swift value-types are copied immediately.
https://docs.swift.org/swift-book/documentation/the-swift-pr...