Ocaml has no ability to do ad-hoc polymorphism at all (but it does have parametric polymorphism), which affects more things than operators, so that's why not only have the weird math operators, but things like string_of_int.

This will change at some point though. Modular implicits are coming to Ocaml. These are similar but much simpler than Scala's implicits, and allow the same kinds of patterns. If Ocaml gets that and eventually gains a bigger community with better library coverage, it's something I would consider using heavily.

That would indeed be good yeah - it sounds like a small thing but it really would help code readability quite a bit, especially when dealing with stuff like bignums.