Disclosure: I maintain PatchWitness, the open-source project used in the reproducible example below.

Coding agents have changed the economics of software modification. Work that once occupied an engineer for an afternoon can now produce a plausible patch in minutes. That is a real advance—but it also moves the bottleneck.

The scarce resource is increasingly the reviewer’s ability to establish:

what actually changed;

whether the patch stayed inside its intended scope;