It may be that you just need something a bit smaller than your full-size keyboard and want to avoid cables that can snag and tangle in your backpack. It could be that the most portable option proves best for you, especially if you're constantly looking for extra room in your luggage for long trips. Since the way you travel and what you travel with can vary, finding the right keyboard to work for you may be tricky. Fortunately, a good travel keyboard can help in these situations.
If you're lucky, you'll at least have a laptop that can give you decent input options, but even that might not be comfortable for long work sessions. You may not always get a full desk to work on, and odds are good that you won't be bringing along your best keyboard, mouse, and monitor. Being constantly on the go can leave you stuck with a tech setup that's less than ideal.