Why do many people bring suitcase?

• Must-have gadgets for business travelers
  http://money.cnn.com/gallery/technology/gadgets/2017/06/16/travel-gadgets/

  As far as my experience on travelling, suitcase is really inconvenient while moving. On flat road, it makes us feel lighter than ruck sack. But, in developing countries or historical area, we rarely see flat roads. Then, it becomes stressful to bring suitcase.
  So, if you hop around many places, I recommend you to use ruck sack instead of suitcase.

  And, the airhook will be useful. I'm always annoyed, every time I have to stow table on the aircraft. Especially when I have a cup of drink on the table, it's troublesome to stow the table.

  I wish there would be more convenient goods for travelling.