I imagine it has something to do with the fact that it's a lot harder to build a robot that can respond to every possible thing that can go wrong in the same wa

I imagine it has something to do with the fact that it's a lot harder to build a robot that can respond to every possible thing that can go wrong in the same way that a human can. If a job is 100% predictable then it can probably be automated relatively easily. Just my $0.02.