I wrote "presumably", but you are 100% correct. I'm always happy to be proven wrong.
N3851 actually deals with multi-dimensional spans and goes way beyond a simple slice/span type. To me it seems closer to std::mdspan than std::span.
The earliest proposal I could find that does propose something similar to std::span dates back to 2012: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n33...
I really don't understand why this was not pursued further. At the very least, this should have made it into C++17 together with std::string_view.
> because of course neither of these were actually proposed as core language features even though that's what they naturally should be
Should it really? What would this even look like in C++? IMO std::span works perfectly fine as a library type.
> C++ is just a terrible programming language, standardized by a committee (WG21) which exists in large part to boost the ego of one man, Bjarne Stroustrup.
That's certainly not the reason why it was standardized. Pre-C++98 was wild west with every compiler offering there own (incompatible) idea of what C++ is. Yes, there are many problems with design by committee in general (and the C++ committee in particular), but there was a very good reason for standardizing the language. The committee is not a one man show and there are many occasions where Bjarne has publicly voiced his frustration and disagreement.