The metaprogramming features of C++ are the killer feature. Only zig comptime comes close. But zig deliberately doesn't allow operator overloading, so high-performance array/tensor programming APIs aren't anywhere near as ergonomic. Since I work in high performance scientific computing, this is a major drawback.

FWIW I was a Rust contributor, pre v1. I don't see Rust as a competitor to C++, but a 'better c' - you can clearly see this by looking at where Rust adoption is highest.

C++ has a boilerplate problem but at least more recent versions have addressed the biggest pain points - 1000 line compiler dumps of of template instantiation errors are less of an issue.