I've seen cases in my career where people knowing the low level things is actually a hindrance.
They start to fight the system, trying to optimise things by hand for an extra 2% of performance while adding 100% of extra maintenance cost because nobody understands their hand-crafted assembler or C code.
There will always be a place for people who do that, but in the modern world in most cases it's cheaper to just throw more money at hardware instead of spending time optimising - if you control the hardware.
If things run on customer's devices, then you need the low level gurus again.
They start to fight the system, trying to optimise things by hand for an extra 2% of performance while adding 100% of extra maintenance cost because nobody understands their hand-crafted assembler or C code.
There will always be a place for people who do that, but in the modern world in most cases it's cheaper to just throw more money at hardware instead of spending time optimising - if you control the hardware.
If things run on customer's devices, then you need the low level gurus again.