I disagree. The entire point of Steam is not having to worry about physical media and keys, not having to download patches and hope it installs correctly or using another system to find servers. The point is all the tools you need are built and/or automatically done for you. Get a new computer, go to a friends house, need more HDD space, no problem. The games can be downloaded with the latest patches and installed for you in less then an hour or two (depending on connection and such) without having to worry about damaged media and lost keys.
So, yeah, you're right. No benefit what so ever.