Unlike regular taxis, with cargo taxis, you pay a minimum order amount rather than paying for the actual time spent. This is due to the cost-effectiveness and expenses associated with using a cargo vehicle.
You can try, as an experiment, to hitch a ride from a truck on the road, and you will realize that it is not easy. A truck is unlikely to respond to you, unlike passenger cars. Finding a vehicle of the right size is even more difficult. You may end up wasting a lot of time with no results. The same can be said for movers – it is unlikely that anyone will want to organize a move, participate in loading and unloading, and be able to do it professionally.