Advantage:

Free your hands: Use a shoulder pet bag to carry your pet safely and comfortably, freeing your hands. This is especially convenient for people who need to take care of their pets and perform other activities at the same time.
Safe closure: Shoulder pet bags are usually designed with a sturdy zipper or other safe closure device to prevent accidental escape of pets while on the move.
Internal comfort: Backpacks are usually equipped with soft cushions or mattresses inside to provide pets with a comfortable resting space to make them feel safe and comfortable during travel or outdoor activities.
Outdoor activities: Suitable for taking pets to outdoor activities, such as walking, camping or traveling. Pets can rest safely and comfortably or observe their surroundings.
Indoor use: In the home, the backpack can be used as a private space for your pet, providing a safe and comfortable place to rest while controlling your pet's range of motion.