I know what you mean, obviously you do have to personally if possible check out information - but so often the help you get on here is really brilliant, and people are so altruistic, giving up their own time and delving onto sites you may not have access to, just to help someone else.
I've had some wonderful help, far more than I've been able to give back, I fear, and so I'm quite willing to hop into the subscription site I pay for, or other resources I may have access to, to try and help others out. People here are also so well-mannered, and thank you, even when you don't feel you've been of much help.
Even when it isn't a simple finding a date or fact, the people on here are so good at thinking round a problem, finding alternative ideas, especially when you're deeply stuck yourself. And also, simply browsing around can be fascinating - and sometimes you suddenly think "Ooh! I know something / someone that can help there..." and that's quite a warm feeling.