The report claims that DeepMind's control experiment found that the simplest Agent A could also solve all 9 Erdős problems, just more expensively on hard problems. In other words, without evolutionary algorithms and without AlphaProof, a single LLM loop plus compiler feedback was enough to cover all 9 problems.
This result runs counter to the intuition that more features mean greater capability, and it directly weakens the narrative of architectural necessity for Agents B, C, and D. The difference given by the report lies in cost: on difficult problems such as #125 and #138, the full version Agent was about 2 to 5 times more cost-efficient than the basic version; all told, the cost of solving one problem was roughly a few hundred dollars.
But these two cost figures are estimates from the report, with no explanation of the calculation basis, and the benchmark and statistical method are unclear. The details and reproducibility of the control experiment itself are also unknown. Therefore, the more prudent reading is: the evidence presented by the report points to 'a simple loop was already enough to solve this batch of problems,' not 'complex architectures are useless.'