People can type better on tablets, handwriting would not matter. Better prepared for life. Textbooks can get worn out. Can't lose homework. Pads take up less space. Saves paper and Ink cartridges. No pencil sharpening. 1000's of apps. Dictionary on board. It would be a lot less space taking than desktop computers.
1. Portability
One 500-page textbook with a hard cover weighs about what, 1 kilogram? Tablets weigh about 0.7 kilogram, and they are getting lighter and better everyday. Here's my favorite part: you can carry too many books, much more than you will ever need, without changing weight. Add internet to the equation...
2. Searchability
Deja vu happens a lot while reading books. Some people, like me, are obsessed in knowing where on Earth have they read this before, especially when cramming for exams. Search is the answer.
Indexes are nice in textbooks, but search is way nicer.
3. Editable
There are a couple of books that you may want to re-read from a different perspective, that is, from your older-self perspective. Removing annotations or having a fresh copy of the same text without buying the book again is also nice.
4. Sync
This applies to books in general and can be applied to textbooks. Leave your tablet or laptop at home and carry on reading using your smartphone in bus or any online computer in the library.