"Is the internet nearing saturation point?".
I think what is reaching a saturation point is that Google only has one SERP page for a particular keyword search and is limited to the amount Paid Ad space on that one page. Maybe in the future they could consider rotating the first and second page for the same keyword entered, but of course that would mean that the value of the second page wouldn't be as high as the value of the 1st page. (Just talking out loud here)
Some searches or pages are a bit more in high demand than others and obviously there are variations of keywords that will pull up different pages, but the point is; there is a limited amount of space available on one page, for a certain keyword that truly converts (I am not talking about garbage KW's), its getting progressively more expensive and pretty soon the barrier to entry will become extremely difficult. There has to be a better way to manage whats coming ahead.