I remember one keynote where he was talking about slowing PC sales and a huge rise in iPad sales (tablets were relatively new back then). Yet he didn't credit the two most obvious reasons - market saturation (everyone already has a PC) and slowing upgrade cycles - today's PCs are "good enough" for many more years than they used to be, as hardware improvements have stagnated.
Years later, the same kind of slowdown happened with tablets (especially Android tablets which are basically dead, but iPad wasn't completely spared either), and will eventually happen with smartphones as well.
The "we are now in a post-PC era" hype of 2010 (after the iPad's release) has eventually led to many "tablets are dead" articles by 2016.