the problem is that doing so would require storing a copy of the entire subset of the internet that you choose to persist, which requires you to either choose a small subset, or pay huge storage fees!
I just bought a 2 terabyte drive for $55, which is mind boggling to an old salt like me. The need to store enormous amounts of real time data will keep driving storage advances. Text and image data may turn out to be a trivial percentage of the overall storage needs in the longer term.
