I think the case you lay out for read2 over read is compelling in the sense that an API like read2 needs to be created for Rust. It may even need pushed into the standard library at some point, and read reimplemented in terms of read2 at some point. That being said, I don't see why it isn't entirely appropriate to create and iterate on such an API on crates.io and only once the kinks are worked out worry about whether or not it belongs in the standard library.
As has been pointed out, even C# with .Net Core is moving more away from a monolithic standard library and more towards a model similar to cargo (Nuget).
You seem to have a lot of low-level, yet, Enterprise-class experience that could be good for the Rust community. I think that no one here takes your insights lightly, I think there is just disagreement about the balance between what needs to be in the standard library vs what needs to be developed and nurtured in crates.io.