A niche provider that doesn't do generative AI very well but does "AI powered search with citations" is perplexity.ai

I've used for rather obscure queries and liked the summary the AI wrote as well as the links to dive deeper. I imagine that's what AI search will look like across all providers before long.

That site looks incredibly good.

I threw in a question Wikipedia does kinda answer but leaves a lot of details off, and it enumerated a set of possible answers, with my favored option linking into a forum where it looks like less than a dozen people post, but with people that tried all variations of it and know all of the details.

DDG and Google would never show me that site (yeah, I've tried).

Just to add, that forum has better answers than the ones GPT created directly on the search engine. If it was a "consult the Oracle" interface instead of a search engine, it wouldn't be useful at all.