Sure full size tablets are still "needed", especially in the living room or other areas, where mobility ain't that important. But they aren't replaced that often as smartphones and phablets: no 2 year phone contracts, even older tablets have "good enough" specs for most people and their batteries don't age as fast as the smartphone batteries (bigger capacity, fewer reloading cycles).
And many people love to shop with tablets: http://www-01.ibm.com/software/marketing-solutions/benchmark-hub/alert.html
Smartphones Browse, Tablets Buy:
Smartphones drove 40.6 percent of total online traffic, more than two and a half times that of tablets, which accounted for 15.9 percent of all online traffic. However, tablets are winning the shopping war. Tablet sales accounted for 18.4 percent of online sales, compared to smartphones, which accounted for 16.3 percent of total online sales, a difference of 12.4 percent.
