Given the choice between
A) having one AI produce a library and having 1000 produce code using that library which comes with tests human in the loop vetting documentation and examples which drastically increase the chance of the 1000 AIs doing it correctly
B) Having 1001 produce the same functionality provided by the library probably on average worse and requiring more expensive hand holding
What in that benefit of B? You might have slightly higher specificity to your use case but its more likely that the only increased specificity is shit you didn't realize you needed yet and will have to prompt and guide the AI to produce.
I fail to see how AI would obviate the need to modularize and re-use code.
I think your thought process is not taking into account what a super logical ai can do, and how effortlessly it could generate some of this code.
Real question: does your world model suppose super exponential gains in intelligence and efficiency?
Using these preexisting will all become outdated. You will look like primitive cavemen if your agents don't build these from scratch every time you build $NEXT_BIG_THING.
Even local LLMs will be able to build these from scratch by end of 2026.
Hyper-optimized HTTP request/response parsing? Yawn. Far less interesting.
AFAICT, the advantages of keeping context tight and focused have not gone away. So there would neeed to be pretty interesting advantages to not just doing the easy thing.
Build times too. I kinda doubt you're setting up strictly-modularized and tightly-controlled bazel builds for all your stuff to avoid extra recompilation... so why are we overcomplicating the easy stuff? Just because "it will probably function just as well"?
"leftpad"-level library inanity? Sure, even less need than before (there was never much). Substantial libraries? What's the point?
Hell, some of the most-used heavily-AI-coded software is going the opposite direction and jumping through hoops to keep using web libraries for UI even though they're terminal apps.