A sleeping bag liner is especially useful in hostels and guesthouses where bedding quality can vary from one stay to the next. Instead of relying completely on shared sheets, you bring your own lightweight sleep layer that feels more familiar and easier to trust.
That extra layer can help travelers feel more comfortable, especially on long trips with multiple overnight stops. Because a liner folds down small and washes more easily than full bedding, it supports better sleep hygiene without making your bag noticeably heavier.