I think we'd have to define "efficient code." Like, not doing something big-O stupid? That's covered in computer science classes and as a science it is pretty human-understandable and timeless. Micro-optimizations? Perhaps between optimizing compilers and massive reorder buffers/massive caches/clever branch predictors, there's not as much need for that sort of thing.

College programs teach both things. Then you go into the working world and it's just not what most people spend much of their time doing, not because of some oversight or deterioration in society or something, but simply because there are more important things to do. And this frustrates a lot of people (especially young people) who loved that part of school and maybe even got into the whole thing because they loved this part of it. Then sometimes those frustrated people (or in order to avoid becoming frustrated), people spend a lot of time on it, even though it's really not the most important thing to work on. And that's fine and all, there are definitely worse things to spend time on, but it also makes sense that a lot of other people spend all their time on the higher priority things.

I don’t know if there’s ever been a comprehensive survey on the subject. But it does seem like a rare skill some times. And it’s not like we’re lacking examples of bloated, slow, and error prone software these days.

Is it getting worse? I don’t know. My impression has been that it’s a marvel it works so well when it sometimes seems like the whole enterprise is too complicated to work at all.

But maybe we have simply been conditioned to not want better. Errors are fine, leaking memory happens, security vulnerabilities are inevitable. What can you do?

Is it worse than it was 20 years ago? I don’t know. I’m not much younger than Blow and grew up programming on an Amiga. I do enjoy fond memories of programming a machine that I had a manual for and knew well. It is very different today… but also much easier and more inclusive of folks with different skill levels.

I don't know if we should necessarily use slow/buggy software as examples. IMO it's very conceivable that it's written by devs who know better, but they're not optimizing for those metrics. I've certainly been in situations where I've thought "well, I can reduce latency here by 100ms, but is that worth delaying the project by 2 days?"