A few things

- since GC languages became prevalent, and maybe high level programming in general, coders arent as economic with their designs. Memory isn't something a coder should worry about apparently.

- far more people code apps in web languages because they don't know anything else. These are anywhere from 5-10 levels of abstraction away from the metal, naturally inefficient.

- increasing scope... I can only describe this one by example, web browsers must implement all manner of standards etc that it's become a mammoth task, especially compared to 90s. Same for compilers, oses, heck even computers thenselves were all one-man jobs at some point because things were simpler cos we knew less.