Frontier LLMs that Google doesn't control are existential threats to Google's business model. If no one is using Google search or browsing websites themselves because they're asking LLMs, Google doesn't make ad revenue. Gemini at least has a path to monetization for Google (subscriptions, ads baked into responses).
A competing model still needs a search index behind it to be a threat to Google. An open weight model doesn’t have that. The other frontier models still struggle to fulfill a lot of queries for lack of one.