As a Belgian, I would tend to agree, except for maybe the South of Europe (Italy for example) whom have far more aggressive driving.
Congestion isn't much worse than you would get in other big cities, except our cities are so close to each other (Antwerp - Brussels : 25 miles) that congestion just flows into one big clusterfuck.
One of the issues is that the highways around big cities aren't bootstrapped for ongoing traffic, so there is no way to swirl around Brussels for example if you just pass by and don't need to be there.
Also Belgium is on the crossroad of many bigger countries ( Germany, France, Netherlands, UK, ...) so our roads are heavily burdened by foreign trucks passing through our country. You can actually see that in the crash clip above. You have a truck driving behind a truck that just passed it, while the accident happened another truck was overtaking the truck with the dashcam, and the car who tried to cross to the exit crashed into another truck waiting on the exit.
This is a typical situation here in Belgium. You could say the driver was not cautious enough and should have been in the first lane sooner. However, I drive that highway (the E40 from Brussels to Oostende - sea side) every day to work and you just have a string of trucks driving one behind the other that stretches for miles.
It's choosing between sitting between 2 trucks for a couple of miles (which really gives you zero chance of survival if the truck in front of you crashes and the one behind you smashes into you) or just hoping the stretch before the exit clears up and you have a safe passage to get into the first lane.