Unexpected productivity boost of Rust

Don't most of the benefits just come down to using a statically typed and thus compiled language? Be it Java, Go or C++; TypeScript is trickier, because it compiles to JavaScript and inherits some issues, but it's still fine.

I know that Rust provides some additional compile-time checks because of its stricter type system, but it doesn't come for free - it's harder to learn and arguably to read

To a large extent yes, but Rust adds more dimensions to the type system: ownership, shared vs exclusive access, thread safety, mutually-exclusive fields (sum types).

Ownership/borrowing clarifies whether function arguments are given only temporarily to view during the call, or whether they're given to the function to keep and use exclusively. This ensures there won't be any surprise action at distance when the data is mutated, because it's always clear who can do that. In large programs, and when using 3rd party libraries, this is incredibly useful. Compare that to that golang, which has types for slices, but the type system has no opinion on whether data can be appended to a slice or not (what happens depends on capacity at runtime), and you can't lend a slice as a temporary read-only view (without hiding it behind an abstraction that isn't a slice type any more).

Thread safety in the type system reliably catches at compile time a class of data race errors that in other languages could be nearly impossible to find and debug, or at very least would require catching at run time under a sanitizer.

Readers would benefit from distinguishing effects systems from type systems - error handling, async code, ownership, pointers escaping, etc. are all better understood as effects because they pertain to usage of a value/type (though the usage constraints can depend on the type properties).

Similarly, Java sidesteps many of these issues in mostly using reference types, but ends up with a different classes of errors. So the C/pointer family static analysis can be quite distinct from that for JVM languages.

Swift is roughly on par with Rust wrt exclusivity and data-race safety, and is catching up on ownership.

Rust traits and macros are really a distinguishing feature, because they enable programmer-defined constraints (instead of just compiler-defined), which makes the standard library smaller.

Swift has such a long way to go in general ergonomics of its type system, it's so far behind compared to Rust. The fact that the type checker will just churn until it times out and asks the user to refactor so that it can make progress is such a joke to me, I don't understand how they shipped that with a straight face.