Having driven a large rig before I can assure you that usually the problem is NOT the big rig driver. It is the idiots in passenger vehicles who cut them off
I do see idiots in passenger vehicles cut big rigs off, but I have just as frequently seen assholes in big rigs cut me off. They pull over to pass as I am rapidly advancing which is already illegal, then they take a literally illegal period of time to execute the passing manouver (in California, if you're not actively overtaking, you must stay out of the passing lane, thankyouverymuchassholes) and then they often lag long after the truck they've passed has flashed their lights to denote permission to merge, just because they're assholes and they can. I also see big rig drivers with a dozen or more drivers behind them fail to use a turnout even on flat ground, which is also illegal in the state of California — when there are a mere five drivers back there, you are required to pull over and let them by, at the first safe opportunity, and not just the first marked turnout. And if I see a big rig hold its lane these days, it's the exception and not the rule. If you can't hold your lane at that speed then slow down, asshole. And if you then hold people up, pull over, asshole.
We all already know that the average truck driver is untrained and unskilled, so there's no need for you to bullshit us. Driver training was already an issue a decade ago because of a lack of experienced drivers willing to sell their life for shit pay, and it's only worse now.
When even half of the truck drivers out there start obeying laws intended to preserve public safety and to make the road usable for everyone, not just freight, then I'll believe your claims that the problems are mostly caused by other drivers. But frankly, you're completely full of shit.