This seems like an incoherent objection – they would presumably prefer to be "Google + LLM" and make less money than let the hypothetical IndexGPT eat their lunch and make even less money as a result, while additionally suggesting that the business model for IndexGPT is poor, raising the question of why it would be pursued in the first place.
You've also not addressed the more fundamental question of why an LLM would even be good for this.