Compiler engineers need to read assembly. I don't think too many people write lots of it by hand, unless they're extending packages like LAPACK of BLAS.

Software has probably been free-riding on hardware, but hardware has also not been keeping up with hardware. The big difficulty is the latency between memory and the processor.

Rust is closer than Go. Go isn't designed to make optimal code. It's there to make good enough code. And it does so very quickly.

In terms of resources, I really like Crafting Interpreters. Would love for you to take a glance at my book (Rust in Action, Manning), if you want to learn about other systems topics outside of compiler design.