Claude Is a Space to Think
Sam Altman responds to Anthropic's "Ads are coming to AI. But not to Claude" ads
Think of the Samsung headphone jack commercial.
Whereas OpenAI seems to be huge in the consumer market (where downward pressure on pricing make ads more likely). They're trying with Codex but all the other stuff (the legal, financial, tooling with cowork, etc) seem to be a lot more fleshed out on the Claude side.
So they can probably get away with this for a while. That's my guess though.