They are useful if you don't care whether the information is correct, don't care where it came from, and don't care that it was stolen from publishers who in many cases invested time and money with the expectation of receiving search traffic in exchange.
Each paragraph/bullet point typically has a little link icon beside it that directs to 2 or 3 sources. I wouldn't rely on it for anything important but it's OK if you just want a quick rundown on an unfamiliar topic and want to check out likely source material.
I understand the appeal of not wanting to wade through 20 links to find information (especially given SEO stuff that is often on top) but why will people continue to publish as traffic decreases due to AI summaries?
I mean I understand the urgent need to keep up but the problem with "theft" is eventually it drives out honest production and everyone is worse off.