Strawman argument.

Standards and patterns matter, but discernment matters more. The issue isn't reusability itself, it's the cargo-cult adoption of frameworks that solve problems you don't have, when you don't have them.

Your LLM agent works for undiscussed reasons because you made deliberate architectural choices for your specific context. That's engineering. Blindly importing a framework just because "everyone uses it" is the opposite. That's the point, nothing more nothing less.