The real competitor is anything inessential that might cost the same price as a tablet. The tablet is competing FOR a small bit of disposable income. Cell phones are considered essential these days, and something that is "not a phone" and is "not food" and is "not transportation" etc, is NOT essential and competes with other non-essential items.

The only hope for the tablet to get into another category would be for it to become a phone or to become accepted as a computer substitute.