This is probably a difficult-to-solve problem; given that they generate billions of these a day, not even Google can afford to devote enough compute to each query to reliably generate quality results. You can see this by selecting the "AI mode" from the search interface after getting the mediocre summary - the results are much better and generally perfectly usable. Though even that is probably a special minimal-compute version of the lowest tier of Gemini, it's still maybe an order of magnitude more capable than whatever generates the search summaries.
The bigger problem is that these search summaries are the default and by far the most common interaction that the general public has with "AI", and because this experience sucks, they just assume that all LLMs are similarly stupid and mostly useless. In non-technical spaces I frequently see the argument that "AI" is not useful for anything, all it generates is garbage hallucinations, and almost invariably they cite some actual terrible experience with the Google AI search summary. I would argue that the strategy of adding LLM summaries to every search is the worst of both worlds - it makes classic search worse while poisoning users against the idea of actual LLM-assisted search.
https://www.dw.com/en/german-court-holds-google-liable-for-f...