I think it will really depend on the topic. There are some topics where the first N search results are some sort of blog spam (some times AI generated), and so the AI summary is as good or better than the blog spam. There are other topics where the AI summary is garbage, and you need to read its sources. There are other topics where the google / duck / kagi search results aren't all that useful any way (let alone the AI summary of them) and you need to know where to look.