Dimension in combination with traffic are the biggest challenge with driving as such.

Complexity doesn’t go down, but up in new trucks, and automation is a big cause for it, because you need to know much more about how a system behaves in order to make it do what you actually want, if it is automated.

The real problem isn’t technology however, but good old corporate greed and the race to the bottom. Drivers tend to be treated and paid like shit, there are a whole bunch of increasingly complex regulations to follow, and getting and keeping a license costs a small fortune.