The argument
Benchmarks are useful because they make comparison possible. They are dangerous when comparison becomes substitution for the real decision.
An agent that performs well on clean, isolated tasks may degrade across a long workflow with tool failures, serial dependencies and changing state. RAMP's 2026 production-grounded evaluation found exactly this pattern: models that looked capable on individual stages deteriorated as work chained together, and none completed the full compiler-construction pipeline used in the study.
Anthropic makes a similar point from practice: agent evals need to cover trajectories, tools and outcomes because autonomy makes failures more complex than a single answer. OpenAI's work on validating public evals likewise argues that real usage evidence helps close a gap synthetic evaluations cannot fully cover.
A benchmark answers, "How did this system perform here?" Production asks, "What happens when this workflow keeps going?"
Why people believe it
Leaderboards compress complexity into a number. Procurement needs comparison. Model releases need a headline.
A single score is much easier to discuss than a reliability surface.
What the evidence says
Production quality depends on repeatability, fault tolerance, tool behavior, latency, cost, recovery and the distribution of real tasks. A system can win a benchmark and still lose your workflow.
That does not make benchmarks useless. It changes their job.
The better question
Ask: Which parts of our production environment does this benchmark actually reproduce, and which important failure modes does it omit?
Use the leaderboard to form a hypothesis. Use your runtime to make the decision.