Take the transformers library as an example. It has hundreds of contributors, is used in thousands of projects, has been downloaded over a billion times. Suddenly, anyone with an agent can instruct it to find some open issue, fix it, and submit a PR. And that's exactly what's happening. Those people feel happy because they are contributing to a great library, but the sad reality is that, most of the time, they don't realize they are not.

Codebases like transformers care deeply about the code. It's cool to build projects where it doesn't matter what the code looks like, but transformers is not one of them. Being used by thousands of people, transformers is primarily built as a human-to-human communication method, through code. Model files read top to bottom, because we want practitioners to understand them without jumping through complex abstractions. This permeates throughout the library design and is the reason why, for example, we favor flat hierarchies.

Agents don't have that context. Because design decisions are not explicit, agents suggest refactors to "improve" the codebase by following "best practices", without realizing they are breaking implicit contracts between the library and its users. They are verbose, generalize too early, don't notice when a change affects other areas, introduce subtle bugs, break performance. They are also sycophantic, and accept any idea as good and follow it through diligently, including ones a maintainer would have pushed back early on with a terse comment.

A small number of maintainers still has to read every PR, understand it, decide if the design direction is right, identify side effects, and write feedback. PR volume has gone up tenfold, but the amount of maintainers has not (and cannot, because team coordination does not scale).