As someone who learned to program on a machine with five kilobytes of RAM, and later had to put a fair bit of effort into unlearning some of the resulting habit

As someone who learned to program on a machine with five kilobytes of RAM, and later had to put a fair bit of effort into unlearning some of the resulting habits: Yes, that kind of efficiency (in terms of machine resources) and inefficiency (in terms of human resources) is effectively obsolete for general-purpose programming. What of that? If your heart's desire is to work in a context where machine resources are scarce, just work in an area like high-performance technical computing where that's still true. We do not, and never will, have any shortage of jobs where you always need more computing power.