Typescript is a strongly typed language built on top of one that isn't, just like Objective-C gets all of the run-time problems that C has if you wanted them or not. There is no such thing as a free lunch.
And if you didn't understand my argument about the fact that Typescript only exists and is used because people are forced to deploy to Javascript-only targets and are desperate to use something that is a bit more sane to work with I don't know what else to say. I've used Typescript, it has some great ideas I would love to see in Swift but at the end of the day the only thing it is is an extension of Javascript, which includes all of Javascript's failings.
If you like languages that have the properties of Javascript, there are better languages out there. Nobody would use Javascript if given an equal choice between all alternatives. Javascript is used because you have no other choice if you want to be compatible with browser-only targets.
Yes the very same way Swift exists because iOS devs are forced to use Objective-C (that have exact same flexibility of js) and Kotlin is simply because there are so many java projects and environments.
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.
And if you didn't understand my argument about the fact that Typescript only exists and is used because people are forced to deploy to Javascript-only targets and are desperate to use something that is a bit more sane to work with I don't know what else to say. I've used Typescript, it has some great ideas I would love to see in Swift but at the end of the day the only thing it is is an extension of Javascript, which includes all of Javascript's failings.
If you like languages that have the properties of Javascript, there are better languages out there. Nobody would use Javascript if given an equal choice between all alternatives. Javascript is used because you have no other choice if you want to be compatible with browser-only targets.