Do you "walk away with" your per mile rate? Or do you have to pay for gas and other things first?
The free market has correctly found that there's a large supply of people who can work as a trucker, but not a huge demand. The market has "correctly" set wages at a subsistence level for these workers.
The slow shipping times are fine too! The market has correctly determined that waiting for goods is preferable to spending more money to guarantee meeting delivery timelines. Great going market!
In seriousness, when you cut compensation to the bone you get impoverished workers and a brittle logistics system. Capitalism pushes companies too far into cost-cutting, and the regulations and unions that used to counter problematic cost-cutting were stripped of power in the 80s.