OCaml has a much stronger type system than Typescript.
The real question is "why not Rust?". I've used both a fair bit and OCaml's only major advantage IMO is compile time. That doesn't seem compelling enough to put up with the downsides to me.
I'm the CTO of Terrateam. For "why not rust", I have found the downsides of Rust not compelling enough to use it. We don't need close-to-metal performance. We don't really need the borrow checker, a GC is fine. We are immutable by default so the borrow checker doesn't help much there.
Great choice by way, I feel too many reach out for Rust, because they lack the perspective ML type systems are not something introduced by Rust, rather a long linage of languages since ML/Standard ML.
Plus, OCaml kept the SML tradition in its robust module system, with modules as first-class citizens and ML-style functors, this is something hard to see nowadays, even among ML-inspired languages.
The sense I get from some comments is that if you need a type system and to compile to an executable, Rust is the only option, otherwise you can use pretty much anything. But, as you say, MLs have been compiling to binaries for decades. One of the first online books on OCaml is for systems programming.
I know that isn't everyone's view, but I do hope posts like this, even if not technicaly deep, at least let people know that there are lots of options out there.
I don’t like OCaml myself, but I’d pick it over rust here as bare metal perf is not necessary, and time wasting fighting the borrow checker is just not worth it.
It is worth it in my opinion because it's mostly a one-time cost (learning how it works and what is allowed), and in return you get less buggy program structures (it basically forces you not to write spaghetti code). Also you have to worry about it much less if you don't need 100% performance and are happy to clone everything.
Occasionally I do still fight it, e.g. if you want a self-borrowing structure there still isn't a great solution (I think Rust should support position independent borrows) but overall it's fine.
Answer is easy, not everyone needs the performance boost provided by borrow checker, 99% of the time some kind of automatic resource management is good enough.
The real question is "why not Rust?". I've used both a fair bit and OCaml's only major advantage IMO is compile time. That doesn't seem compelling enough to put up with the downsides to me.