What is it that the C/C++ development community is catching up to?
(And also, I'm not convinced that programming languages should be treated as having their own isolated developer communities, considering there is often a lot of overlap. Are we talking individual users? Companies? Language designers? Etc.)
Good support for multi-core programming comparable to what java.lang.concurrent, language thread and network async IO offer.
C++11 introduced std::thread, with a couple of issues retified in later revisions, and apparently executors just failed C++20, delaying the introduction of a major part of async networking.
Language safety as well.
For me, in spite of the safety improvements in C++, I see the language being tailored for specific niches and no longer a full stack language, similar to how it is handled on modern desktop and mobile OSes.
(And also, I'm not convinced that programming languages should be treated as having their own isolated developer communities, considering there is often a lot of overlap. Are we talking individual users? Companies? Language designers? Etc.)