I changed browsers in the past and a big reason is because they started to suk. If search doesn't fulfill my needs and something else does I will switch. Currently my needs for search are 100% fulfilled by google so there's no reason to switch. I don't think AI will change classic search too much. I think they will take some market share as Edge is often already mandatory in cooperate and that might widen now. It's not a major game changer like many think for search but it can be game changer as a standalone development like direct windows integration.