Comment by dcode

To me it's not so much a question of what's the best / recommended (for new languages) / most used encoding. It's rather the observation that there are so many popular languages operating on Unicode Code Points, not Unicode Scalar Values, and Wasm said it wants to support these (as) well, incl. integration with JS/Web APIs which already share their semantics. And for all of these, the restriction is unnecessary and trivially avoidable by allowing them to pass strings to each other, or from/to JavaScript, without errors or mutation, while not changing anything for those preferring UTF-8. Looking at this the other way around might be valuable as well: What if one would design a Component Model for any of the affected languages? There, introducing an unnecessary discontinuity would be a design mistake I'd argue.