> Others are rightly pointing out that only #3 is fundamentally unique to Rust. All of these other things could be done for C++. But, importantly, they haven't.

Except they have, but some people aren't keeping up with C++ news, only bashing it.

1) can be easily done with bounds checked enabled STL, like modern C++ compilers do in debug builds, or force enable them in release builds.

2) Conan, vcpkg, and better than cargo, because they support binary dependencies.