My SO did soil testing for the state for public works projects. Things like water retention rates, expansion, Atterberg tests, etc. It's incredibly basic stuff. Like, how much does the soil expand when it rains/snows? Over a few hundred miles of road bed, even small percentages will add up. In our state there are clays that will expand 4x their volume before water can no longer be absorbed. It turns out, the earth can be suprisingly active on a week to week basis, just from rain.

So, yeah, there is a LOT of corruption and incompetence out there. But we've figured out a lot about soils/rocks/dirt in the last 40 years or so too. It's that there is this deep perception in most people that dirt is well ... dirt. Like, it's dirt, it doesn't change or move.

So, you get issues where they pave the road-bed over just after a rain. And then the road dries out over 2 years and the entire road just breaks apart. Or you get the problem where the the pH of the soil wasn't tested, so the rebar in the concrete will corrode faster. Or they build another thing nearby and change the drainage patterns around your dam. It's not simple stuff to make a house or a 70mph highway that will last for 50 years without a lot of issues.

Honestly, it does take a PhD these days.