Today, that iPad has cracks in the screen from the minor bumps and scuffs it's taken over the years. After several iOS updates it's become slow and tedious to use. Wifi reception is terrible so I often have trouble using it when sitting in bed, exactly one floor above my home router. Opening more than one or two tabs in the web browser causes each one to reload when switching and overall performance is barely acceptable.
Contrast this with the less expensive Asus laptop. My girlfriend still uses it as her sole personal computer and runs Office apps, connects to her work VPN for access to company resources, uses it to watch movies on Netflix, browses the web, and plays casual games. It runs just as well as it ever did and while there are also minor scuffs on the housing, the screen has no sort of cracking and the touch input still works as it always has.
I think that a big part of this has been how iPads and the more "appliance" style tablets have gotten more capable but so have more traditional notebook and desktop computers. Likewise, the performance you get from budget/entry class computers continues to go up even as hardware stays cheap.
At some point, the whole "post-PC" thing will happen as the traditionally "non-PC" devices continue to become more capable up to the point where they can do 90% of the average PC user's tasks. But then, aside from the inability to customize or upgrade, what makes them not PCs?