Driving trucks is more difficult. For instance trucks are mostly (all?) unsynchronized manual transmissions. They take skill and experience to operate.
It's also more difficult safely braking/turning/accelerating a very heavy load like a loaded trailer as opposed to a passenger vehicle.
Some local trucking businesses in my area are training people to drive since there's a shortage of drivers. It takes a while to get someone to the point where they can get their commercial driver's license.
Long distance trucking is also mentally strenuous. I don't know how many of these people do it over extended distances, but I don't think it's very humane to give teenagers a job where they'll have to shit in plastic bags and take speed to stay awake for days to meet their deadlines.
It's also more difficult safely braking/turning/accelerating a very heavy load like a loaded trailer as opposed to a passenger vehicle.
Some local trucking businesses in my area are training people to drive since there's a shortage of drivers. It takes a while to get someone to the point where they can get their commercial driver's license.