OpenAI still needs to figure out how to position ChatGPT and Codex. The two should really stand on equal footing, and Codex arguably has much more room to grow. Folding Codex into ChatGPT can only be a temporary measure.
Anthropic doesn’t have these problems: from models to products, everything is unified under the Claude brand (models Sonnet and Opus, products Cowork and Code). The branding and product lines are clear.