You clearly have more experience with Rust than I do, and maybe you set the bar for 'rigour' higher! In languages like Python, where you might run into an issu

You clearly have more experience with Rust than I do, and maybe you set the bar for 'rigour' higher! In languages like Python, where you might run into an issue caused by not have implemented an arbitrary method on a callback, or Obj-C where you might have forgotten to implement a delegate, you're on your own as far as the compiler is concerned. Yesterday my Rust code didn't compile because I was missing a bound on a type parameter on my function that I passed though into the key type of a hashmap. Rust said "hey maybe you want to add this constraint to your declarations". Some of this you can put down to dynamc vs static. But beyond that, it's clear that the designers and contributors haven't just said "we want to make a language with great safety" but then went on to ask "what specific ergonomic challenges will this bring to users, and how do we help them" . I don't think you could get those ergonomics from many other languages, even if you wanted, without extra static analysis. (edit: lazy typing on a phone; in the last para I was referring to the mainstream languages like Python rather than the whole universe of languages.)