Data on search engine market share is available, but I wonder what that looks like for Lemmy users in particular, who I would assume lean more technical than the average user, so probably use DuckDuckGo and alternates more than Google.
I use a mix of DuckDuckGo and Kagi. I'll also use ChatGPT, which can be good if you're careful to verify the answers it gives you as a check against hallucinations. It's useful for short, direct answers without ads or SEO bullshit.
I can see a usecase for where you don't know where to start or search with, and then verify with actual searches.
I recently used it to explain for a friend what is the difference between wheat and ale beer, and it gave a very good summary. With DDG I might not get a direct explanation and would need to read a few articles and then word them in a comprehensive way.
If you pay there's an option for chatgpt4 that can use Bing to search. There's also various plugins that can let it interact with all sorts of additional data sources. Not that you should use it like a search engine exactly, but it can be useful for search if you configure it correctly and understand that it doesn't "know" anything.