Yes! There a lots of great reasons to carry a landing pad with you when you go out to fly.
The top reason is, you will have a clean, flat surface to take off on regardless of the ground beneath the pad. For example, if you want to take off on a beach, without a landing pad, your drone would stir up sand and dust that could damage the motors and camera. Placing a landing pad down (using the included pegs, to ensure it doesn't blow away) means your drone is not going to take on sand when the props spin up.
Some drones sit so low to the ground, that even short grass can interfere with the propellers. This leaves the chance for dirty props, at the very least, which can interfere with the efficiency of the drone, and damaged props, at worst, which could lead to a crash in a worst-case scenario.
Another great reason, is for drones with downward facing cameras for precision landing (for example, the DJI Mavic Pro), it gives them a reliable target that they can easily "see". Trying to find the exact landing point on grassy terrain, or any terrain which is relatively uniform in colour and texture, means the drone probably won't be able to find the exact landing point, from which it took off.
Landing pads fold up to a very small package, and usually come with a small carrying bag. (Tip: to fold up your landing pad, hold the landing pad with your hands at opposite edges and simply "twist" the pad - it will fold up into a circle that is one third the size of the original pad diameter). So they are small, lightweight and easy to carry along.
For the small price, a landing pad is a great investment that will ultimately extend the life of your drone!