It was used in Google translate, and BERT was incorporated into search in 2019, though I don't think it was a clear win for search, I feel like I started having to add exact quotes to everything technical/programming around then.
E.g. when I start a search session to solve a programming problem (before llms), I will continually search different terms to get to my solution webpage. Then stop. This session metadata and the path I took is highly significant data that can be used to help llms recognise what research itself looks like.