A reduced version of this is maybe where Go and Rust have a pretty similar contract for things that “Read” and lean hard into permitting partial success. Both allow for some relatively sharp edge cases with zero-sized reads.

The contract is always right … how well it is expressed through language mechanics is maybe another way to contrast things here. (FWIW I think Go could tighten up a few things - dropping or shadowing errors is a bit worrying - but I’m fairly convinced sum vs product is a little too harsh of a reduction; a useful distinction but not a complete one.)