This is very interesting. I know Intel has their own compilers, but wouldn't seconding a couple engineers to the GCC/LLVM teams yield exactly the benefit you're describing here? It's a trivial cost to boost their own add-ons.
On the bigger point, it ends up hurting them because companies often use gcc to benchmark across systems, so the Intel performance comes out lower than it might be if Intel really invested heavily in gcc rather than icc.
So now Intel chips are limiting battery life because every application is executing unoptimized garbage that runs longer and therefore uses more energy. Meanwhile, Apple Xcode will produce optimized binaries for Apple Silicon and the press will go wild.