Well, you are overlooking the language itself: how nice is it to code in, does it help you iterate more quickly, and how much does the awesome type system help you prevent errors, refactor code more easily, and promote stability over time?

These answers will vary wildly from person to person, but for a lot of people the answers to those questions will definitely provide a "good reason to move away from Ruby on Rails, Django, Node, etc."

I agree with you that the advent TypeScript is strengthening JavaScript's position immensely. TypeScript is really awesome. But it is still a type system bolted onto JavaScript, and it being a strict superset of JavaScript — even though that was a great design decision on balance — means it just can't do as much for the programmer as Swift can in that regard.

But if you wanted a comprehensive type system then why not Scala.

You get similar syntax to Swift whilst leveraging the best server side libraries available on any platform.

I learned enough Swift to know that I think it’s terrible and that I really don’t like the way that Apple designs anything. They couldn’t get strings right the first time because they were too pedantic about how I should think about them, they prefer all sorts of weird shortcuts that make code unreadable, like trailing closures, if-let and some other things I can’t remember and the tooling is clunky, slow and generally sub-par to my preference. I think Xcode and Mac OS are the worst and I’d probably kill myself if I had to actually code with them instead of just using them to compile stuff like I do now with my React Native projects.

I’d rather use just about anything else. If I could use C# everywhere, I would because Microsoft really knows how to cater to developers like no other company and their tools are second to none in many cases.

on the other hand , if let and guard let , together with optional, is what makes swift the safest language i've ever developped with relative to null pointers exception (I haven't had any in years) yet bringing almost no syntax overhead.

Compare that to go ( which still has npe) or rust ( whose borrow system appears to be a real pain point) and i think it has an edge.

Have you tried crystal? It has much of the same in how its union types work.

Performance-wise server-side Swift is miles ahead of Node and Django. Apart from that, the tooling is indeed terrible...