Untrue. Typescript uses Javascript as it's runtime so inherits all of it's problems, Objective-C and C are 100% transparent to each other and for real masochis

Untrue. Typescript uses Javascript as it's runtime so inherits all of it's problems, Objective-C and C are 100% transparent to each other and for real masochists it's even possible to call Objective-C from C with an awful and clunky API. So you'll find most of C's problem in Objective-C while it's a much nicer to use language to express business logic and definitely much more compiler safe. Kotlin uses the same JVM as Java and inherits some of it's limitations (around generics for example). Swift has it's own run-time and used to ship it with every app built in it before the ABI was stabilized (and is still added for older versions of macOS and iOS if you target them). It still needs to interface libraries written in C and Objective-C and for that reason some parts of the language aren't as clean as I would like to see it, but otherwise UIKit and other libraries wouldn't have been compatible.