HPC is all about C, C++, Fortran, Python (as scripting language), and now Julia is slowly being the new kid in town.
Stuff like OpenACC, OpenMP and MPI are expected to be in the box, regardless of the language.
On the graphics space, Khronos, NVidia, Intel and AMD are driving the adoption of standard C++ as compute language.
NVidia now has many key contributors to ISO C++ on their payroll and as shown at GTC 2022, wants to make CUDA the best GPU implementation of such features.
Then on game consoles, C++ is the main language on the SDKs, alongside C# and Unity.
One can naturally use other stacks, like Embark Studios is doing with Rust, but then it is on them to spend development resources on making it work, and deal with possible integration issues.
Most of the interfaces you're discussing are more-or-less "purely functional", though. Interop overhead is going to be a lot less when you're squaring a matrix than when you're trying to write an event loop. In fact, most people who use those C++ libraries never touch C++, as you've pointed out yourself: they use Python or (recently) Julia. The ecosystem as it exists is already a hodgepodge of C[++] and Fortran, and while the interop between those might be annoying if you were building a video game, a NumPy user doesn't care if one subroutine is in C++ and the next one is in Fortran. So, I don't see why one more backend language would be a problem, realistically.
Hiring, team knowledge, vendor support, there are better things in a researcher lifen than writing interop bindings, community support to review papers,...
They will find that their Rust experience is worth little, because they will need to go back and learn C++ to make any progress in those, and indeed most areas.
I guess one advantage is that it's a lot harder to get (safe) Rust that compiles while doing something awful with regards to important subtleties of C++ not obvious to a "C with classes programmer" (e.g. Rule of 5 stuff); my university's everyone-takes-it C++ class made essentially no attempt to teach this stuff past mentioning it.
University programming education is a dumpster fire. Teaching C++ as "C with classes" amounts to malpractice and student abuse, and in a better world would generate dismissals and even lawsuits.
Beginning students are, by definition, by far the least well equipped to understand what would be most beneficial to learn. That universities fail to step up is a disgrace. Those students who learn Rust instead of C++, or "C with classes", will graduate very poorly equipped for what will be expected of them.
