The expectation in the HPC community is that an interested vendor will provide their own BLAS/LAPACK implementation (MKL is a BLAS/LAPACK implementation, along with a bunch of other stuff), which is well-tuned for their hardware. These sort of libraries aren't just tuned for an architecture, they might be tuned for a given generation or even particular SKUs.

Each vendor. Intel BLAS (MKL) has Intel-specific optimizations and AMD BLAS has AMD-specific optimizations.

Intel is still acting in bad faith by allowing MKL to run in crippled mode on AMD. They should either let it use all available instructions or make it refuse to run.