Nobody knows everything, even about a specialized subject. There's just too much.
In fact, there is now so much information out there that when you need an answer, you aren't even sure where to start looking.
A trained researcher can help you find it faster-saving you hours of precious time.
The internet is a great place to do research. The only drawback is that there's so much information out there that it's hard to separate the wheat from the chaff.
Even the best search engines, like Google, can drown you in results that take hours to go through. After years of doing research online, I know how to find things quickly.
As useful as the internet is, libraries are far from obsolete. For detailed, reliable knowledge, books very often have the edge.
If you need answers that can't be found online, I can go to one of the many Bay Area public and university libraries and find them.