The main reasons for bringing a laptop are for work, photography, and/or blogging purposes. If you have a travel blog, whether for fun, family, or business, it’s much easier to keep up with if you have your own laptop vs. trying to do it on your phone or a tablet. If you like taking a lot of pictures, it’s nice to have a laptop so you can regularly download them from your camera. You can then easily back them up to hard drives or upload them to your favorite cloud service. Besides that, a laptop is a great gadget for entertainment. Some people like to be able to keep up with their favorite TV shows, movies, and sporting events, and having your own laptop allows you to do that, though you can do the same with a phone and/or tablet, so bringing one solely for entertainment might not make sense.
But is the extra weight necessary if you have a smartphone or tablet? If you do bring a laptop and you have a choice, you should definitely take the smallest one you can manage to bring. Every ounce of weight you are dragging around gets multiplied when you are literally hauling every possession on your back for months on end. There are risks with taking your laptop with you It’s one more expensive item you have to carry with you and risk getting broken, lost, or stolen. Laptops are fragile. One drop and it could be totally done.