A advantage when investing in a 3 piece luggage set is the ability to have various sizes of suitcase that can be used in various situations. A lot of the times you might not need to bring a huge bag with you, but previously it was the only one you had.
With a three piece luggage set, you are going to have three different sizes that you can choose from, anytime you need to travel. This will allow you to be able to use the luggage bag that is the right size for that particular trip.
Not having the right size bag can end up causing you to pay more at the check in. And not having to lug around a big heavy bag unnecessarily.
You gain flexibility when you invest in a 3 piece luggage set.
Next up… Expandability