I think other explanations replying are on point. I live in a town that's surrounded by a lot of farm traffic, and most of those roads are in good shape. But there are also routes used heavily by trucks servicing fracking sites, and those roads are TRASHED.

My grandma used to live close to a road servicing an oil derrick, back in 90's Romania (so 0 infrastructure investments for probably 10 years).

At one point my family was in a Dacia 1310 (crappy and very cheap Romanian car) and we literally went very slowly (probably 10kmph) through a section where the road was basically sunk, there was a "pothole" probably 10-15m long and 80% of the road wide (both lanes), about 1m deep, I think.

The funny thing is that there were potholes inside the uber-pothole :-)))