>And that is why [...] C++20 modules are still full of warts, working on Visual C++ (kind of), and not really anywhere else, as ISO C++ has long stop being about standardizing stuff with actual field experience.

Yes, but your complaint about flawed C++ standards or incomplete implementations is orthogonal to what I was writing about.

I'm just explaining that the C++ committee doesn't have the power to impose changes that some people think it does. Basically, I'm saying "the sky is blue" type of statement. The C++ committee is a reflection of what the members' compiler teams want to collectively do. The committee doesn't have unilateral supreme power to dictate standards to compiler teams not interested in it. Instead, they collect feedback from people sharing proposals in papers and put things to a vote. The compilers' teams have the real power and not the committee.
(What I've stated in this paragraph should be uncontroversial facts but the downvoters disagree so I'd love to hear them explain exactly what power and agency they think the C++ committee actually has.)

If one understand the above situation, then the following different situations shouldn't have any mystery as to cause & effect:

- How did the std::chrono get added to the standard library? Because Howard Hinnant made a proposal with working code, and others liked it enough to vote it in.

- Why is there's no _standard_ cross-platform GUI and audio library in C++? Why is there not standardized Safe Syntax C++ like Rust? Because nobody has made a proposal that convinced enough of the other members to agree to a x-platform GUI and audio framework.

- Why does C++ committee adds features and prioritizes things I don't care about? Because the <$feature$> you cared about wasn't proposed for them to discuss and convince others enough to vote it in.

But yes I do understand the "warts" complaint you're talking about. It's frustrating that the std:regex with bad performance got approved. In similar examples, N Josuttis in multiple conference videos has complained about the problems with ranges and views. He says it was wrong for the C++ committee to approve it. (footnote: The original author of the proposal tried to explain his technical rationale: https://old.reddit.com/r/cpp/comments/zq2xdi/are_there_likel...
)

To reiterate, I'm not trying to explain away bad language standards. New features that will have flaws will continue to happen in the future whether it's created by a singular corporation like Apple(Swift) or a cooperative group like the C++ committee.

I'm just explaining why some "wishlist desirable C++ feature" isn't going to be in the standard if there's no proposal that convinces the other members to vote it in.

EDIT to reply: >When we complain about the "committee" [...] the things they choose to propose and vote for.

The C++ committee members are not static but the webpage has list of names : https://isocpp.org/wiki/faq/wg21

Clicking on various PnnnnR.pdf proposals that motivated each feature in the conformance table shows most authors are not from the actual committee members:
https://en.cppreference.com/w/cpp/compiler_support

Using the above workflow to address your complaint about std::span and at(), I found this comment from the original author Tristan Brindle who proposed it and why he thinks the committee voted no:

2019-10-18T22:55:30z
https://old.reddit.com/r/cpp/comments/djqdu2/why_is_stdspan_...