"There's little benefit to writing your own asm these days"
Agreed, but programming in ASM makes one think differently. In my opinion every programmer should do some elementary Assembler as part of their training, say some basic projects based on 8086 stuff or even the simpler 8085/Z80 etc. It's a long while since I've done any serious ASM work but the techniques one learns and the ideas one develops frame important attitudes that can't be easily gathered from high level stuff (one gains a better understanding of the underlying hardware and such).
You're right, we still need people for this work, it'd be pretty hard to optimize a compiler without them methinks.
FYI, there's stuff I omitted to mention in the above comment, I mentioned it below in my reply to bitcurious. It's interesting 'fitness for purpose' arises given your ASM comment.
It's the same here. Without people who deeply understand a tool's input and output, we won't ever write a better tool.
[1] don't @ me, cryptographers and kernel programmers.