There was never any reason for it to be slow in the first place, yet here we are. In my view, we have slow software not because knowledge of optimization comes

There was never any reason for it to be slow in the first place, yet here we are. In my view, we have slow software not because knowledge of optimization comes at a premium, in fact, most compilers do well enough at optimization that you can rely on them for at least acceptable levels of performance, assuming you choose effective algorithms for the task. Software is slow because other incentives are stronger than performance, and people more often make sets of technical choices that produce slowness (for example, opting for ease of development and portability over performance (see electron)). I don't think LLMs are going to change this. They won't change what companies and individuals value. Yes, they can enable those interested in performance to write even more performant software, more easily, but they won't convince the people who aren't prioritizing performance in the first place to prioritize performance. This ship sailed a long time ago. Performance was prioritized when it was necessary due to resource limitations. As soon as those lifted, performance was deprioritized in favor of other properties. I doubt the balance will really be restored until limitations re-emerge or consumers put pressure on companies around performance. Unfortunately, the past few years have shown that the latter is unlikely to work.