As of 2023, Google Search has 91% market share in search engine, when the second most popular search engine only has 3% market share
https://www.reliablesoft.net/top-10-search-engines-in-the-world/
Will Google Search still be the most popular search engine by 2040?
Data source for resolution not determined yet. In 2040 myself or a mod will find a credible data source on users statistics of popular search engines and resolve this market base on that.
If certain LLMs end up powering a major feature of a search engine, whereby users' inputs return a list of websites as output, these would also be considered a search engine as well. However, only the usage volume of the search engine feature would count into the market share.
Inspired by this poll of @firstuserhere: