I would instead state that the standard for what constitutes a "decent compiler" has risen. For any given performance target, I'd still bet that it takes less

I would instead state that the standard for what constitutes a "decent compiler" has risen. For any given performance target, I'd still bet that it takes less work to hit it with a C compiler than with a compiler for most newer languages. (Partly because the success of C has resulted in C-related hardware design constraints...)