Some like Phind or Perplexity cite their sources. And they give you directly the answer you’re looking for without having to search it in a mess of “subscribe to our newsletter”, “other articles that may interest you”, 3 paragraphs of “if you read this article, you will know what you want to know”, “special promotion for you”,…
It doesn’t interoperate well with FOSS software like K9 and Thunderbird.