That depends on how you plan on using your vehicle. Roof racks work best for owners who want to mount things like a bike, kayaks, or other outdoor equipment. Most cargo boxes are also going to mount onto roof racks, unless they’re specifically designed for your vehicle.
The combination of a roof rack + other storage components can be over budget for many people. A quality hard shell cargo box can easily run 500 dollars, or more in this case. You get the benefit of having a secured load that is going to be more aerodynamic, but it’s also not as easy to remove as a soft cargo carrier.
You can even mount bikes on the back of your vehicle if you want and use a soft top cargo carrier on top. There are plenty of hitch bike lock designs. In our opinion, a soft top cargo carrier is by far the most economical option for additional carrying space.