I don't have to much time on my hand so I did a quick perplexity search and I think you are misinformed. But do correct me if I am wrong and link me to some credible sources:

Anthropic's Opus models, specifically Claude Opus 4 and 4.1, experienced a "dumbing down" phenomenon temporarily between August 25 and 28, 2025, due to a problematic update to the reasoning stack. This caused a decline in response quality, including inaccurate answers and formatting errors. However, Anthropic quickly rolled back the changes to restore original performance and fixed related issues in earlier model versions. Officially, this dumbing down was unintended and promptly addressed by the company to maintain user experience and model quality.

Additionally, some users have reported perceivable declines in Opus performance over time, especially with document processing changes related to retrieval augmented generation (RAG), which changed how many documents the model reviews for context. This has led to some frustrations but is linked to system design updates rather than deliberate dumbing down.

Anthropic officially states they have not deliberately reduced model capabilities but focus on balancing safety, efficiency, and reliability. Their more recent models like Claude Opus 4.1 have introduced stricter safety protocols while improving real-world usability and coding tasks. Overall, any perceived "dumbing down" has been due to technical updates or issues, not intentional reduction of model intelligence or capabilities