I 100% agree. Although I have a keen interest in Rust I can’t see it offering any unique value to the GPGPU or HPC space. Meanwhile C++ is gaining all sorts of support for HPC. For instance the parallel stl algorithms, mdspan, std::simd, std::blas, executors (eventually), etc. Not to mention all of the development work happening outside of the ISO standard, e.g. CUDA/ROCm(HIP)/OpenACC/OpenCL/OpenMP/SYCL/Kokkos/RAJA and who knows what else.

C++ is going to be sitting tight in compute for a long time to come.