We're on a road trip through 7 western states and have seen that sort of thing all too often.
In Idaho, a guy passed us at something like 75+ mph towing a vintage Airstream about 25' long with an old SUV. You gotta know he's gonna have a blowout sooner or later. We pulled into a mall parking lot for a break and saw him there - No WDH and the tongue & bumper were nearly dragging on the ground. If he kills himself that's one thing, but endangering others on the road is so wrong.
In Utah we met a family with young kids triple towing at a stop for lunch - truck, FW & speedboat. Owner said it was 81' overall. He passed shortly after we left and he too was doing 75+ mph. I can't imagine what would happen if he ever had to make a sudden stop at speed or got hit by a rogue gust of strong wind. Technically they weren't speeding AFAIK as the speed limit for anyone is 80 mph.