That's got to be worth something, since Alphabet is a $1.7T company mostly on the strength of ads associated with Google search.
GPT is very useful as a knowledge tool, but I don’t see people going there to make purchasing decisions. It replaces stackoverflow and quora, not Google. For shopping, I need to see the top X raw results, with reviews, so I can come to my own conclusion. Many people even find shopping fun (I don’t) and wouldn’t want to replace the experience with a chatbot even if it were somehow objectively better.
People stopping to use google for the small stuff will be the beginning of the end of google being the mental default for searches.