I think the tablets still has not evolved to such a stage that they can replace a laptop. Yes, they are eating up the Laptop's share to some extent. But it will still take to get more productivity out of tablet like the laptop does. Tablets do offer good productivity features, connectivity features, portability, touch screen and good battery life. But still they lack some essential features of a Laptop. Reasons I think for the statement - Tablets are still not a perfect replacement for a laptop:-
1.Tablets come with very low storage capacities when compared to a Laptop. It would cost around Rs.55, 000 (approximately) for an iPad 128 GB version. But you could get 1 TB of storage in a laptop for a price much lesser than that.
2.Screen size is also the area where the tablets fail to replace the Laptop. Laptops provide more real estate for you to work on when compared to the tablets.
3.Tablets carry security issues with them. They are not as secured as the Laptops and Desktops.
4.App availability is another area. iPad has its refined ecosystem of apps but they do not always offer the productivity offered by the pc software on a Laptop.
5.The mobile operating systems like iOS and Android may be the leaders in the mobile market. But they are not evolved like the Desktop Operating Systems like Windows and Mac OS.
6.Tablets do not provide those extra ports and drives the laptops offer. Laptops offer disk drives and more USB ports than a tablet.