The standards have dropped dramatically over the years for driver training. Now they have auto slack adjusters air dryers anti lock brakes which are good things to have but at the same time they give a sense of security that things do not need to be checked manually like days before. All of these things need to be serviced and monitored.
At least these guys have had some training whether they are professional or not.
A point I made earlier is that anyone can jump in a DP with air brakes and drive it down the road with no prior experience or knowledge and think that is ok. Most DP's are just as heavy per wheel as a semi and have no more braking power than a semi. Hence greater stopping distance and more heat build up on down hill grades. They have the same air system as a semi other than trailer brakes and yet a truck driver needs to pass a test to qualify!