Statistics from the National Truck Equipment Association indicate commercial (cargo) van sales increased by 56.7% between 2013 and 2019, and there's no sign of that trend slowing down. While cargo vans are becoming more and more common for delivery services (if you've had an Amazon delivery lately, you know this to be true), they're also widely used by businesses of all types as service vehicles.
Larger vehicles, such as box trucks, will always have a substantial market position for their advantage in capacity. This is especially true for delivery services as their size advantage allows for the delivery of larger items and helps to minimize trips. However, cargo vans generally cost less to purchase, and their smaller size makes them more fuel-efficient and able to fit into tighter spaces. This economy and agility make cargo vans a better choice for delivering smaller parcels and for use as service vehicles.