I see people traveling with backpacks frequently on my travels and many times when I talk to people about where they have been on this current trip they haven't gone anywhere that would require a backpack and to me this is just silly. You don't have to actually wear a backpack in order to be a "backpacker" in the travel world and at least in my opinion a backpack is one of the most uncomfortable and terrible forms of luggage that exists. I have been traveling for over 2 decades and will openly admit that on many of my trips, the backpack wasn't actually necessary based on where I was going and these days, I don't even use a backpack at all. Suitcases have evolved to the point where unless you are trekking to some far away location, there really isn't much reason to ever use one of the traditional budget-traveler backpacks anymore.
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wouldn't a rolling suitcase make a lot more sense in this situation?
I have been all over the world and traveled to every continent other than the really cold one that nobody except small teams of researchers go to. In all of these travels a rolling suitcase would be much better than a backpack. There are a couple of reasons why I say this.
For one thing, there are the wheels and this much should be obvious. It is much easier to pull a suitcase than to wear all of your junk on your back and there have been many times where I have seen people really struggling with the weight of all of their gear and all of this could be solved simply by not using the backpack in the first place.
Most of the places that backpackers go to have transportation and pavement all the way up to where their lodging is and none of this involves climbing over stuff where your luggage would need to be attached to you.
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Also, it is a lot easier to access your gear in a traditional rolling suitcase. When I was using a backpack these things are normally one giant tube with access only from the top. Everything just gets stacked on top of everything else and this can get a bit nasty when you are dealing with some of your clothes being dirty, and some of them not. I've also had a few instances where soap and toothpaste or other toiletries busted open under the weight of all the stuff on top of it and this was just disastrous. Have you ever tried to wash a tube of toothpaste out of your clothes? Well trust me, it isn't easy.
For most people who aren't going somewhere like India or Nepal, a rolling suitcase with a small backpack or daypack would be a much better choice for luggage. Chances are, you are going to arrive at your hostel and then if there is some hiking that is going to be done, you don't need to bring all of your stuff with you and you can just put the essentials in the small backpack for the day. Hell, I took a rolling suitcase with me to Nepal and just stowed it at a hotel in Kathmandu and used a much smaller backpack for the mountain trekking. My friends at the time thought I was making a mistake but by the end of our 10 days journey into the mountains they all agreed that my idea was better. They were moaning about sore backs because they brought everything with them and I was just laughing with my 5lbs of gear that I effortlessly carried around.
I don't think that there are many situations left in the world where a backpack is actually beneficial, let alone necessary. I have to admit that I scoff a little bit when I see people that are trudging around a massive backpack in intense heat when if they simply been a bit smarter about it, they would be lightly tugging on a rolling suitcase and using far less energy in the process.
If you are not convinced by my experience then at least have a look at a hybrid rolling backpack with fully zippable sides.
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The only instance that I can think of where people would need a traditional backpack would be situations where they are going to be camping or going on long hikes to their destination with all of their gear and the weather-proof nature of the packs themselves are very beneficial. These situations are very rare for most backpackers but if you do encounter them they normally aren't by accident.
I think that people who go with gigantic traditional backpacks are making their journeys more difficult and I travel at least 50% of every year. I don't even have a big ass backpack anymore and like Johnny Cash said "I've been everywhere man!"