[mtzet]

In my experience the important libraries I need to interact with are C libraries, not C++ libraries. Of course certain niches have very important C++ libraries, but I don't think the C++ library story in general is that great. Care to expand?

[fsloth]

Not OP, but several domains have large non-trivial C++ codebases. For example, numerics, computational geometry and computer graphics have large mature libraries that would need to be rewritten by subject experts. The number of subject experts in these fields is not that large to start with, and the algorithms are complex and non-trivial, so "exothermic" explosion to new languages like Rust is unlikely to happen very fast.

[pjmlp]

CUDA, SYSCL, DP++, Qt, MFC and WinUI, Metal Shading Language, DirectX, most COM APIs in Windows, WinRT infrastructure, macOS IO/Driver Kit, ARM Mbed, Arduino, the native implementation of most well known ML libraries, all major game engines middleware, LLVM and GCC, just from the top of my head.

[ziotom78]

Not the OP, but the first libraries that come to my mind are Qt and wxWidgets (for GUI programming).