Gemini's Deep Research is very good at discriminating between sources though, in my experience (haven't tried Claude or Perplexity). It finds really obscure but very relevant documents that don't even show up in Google Search for the same queries. It also discounts results that are otherwise irrelevant or very low-value from the final report. But again, it is just a starting point as the generated report is too short, and I make sure to check all the references it gives once again. But that's where I find its value.