It is profitable for them to do that because the cost of energy is still too high.
No, it would be profitable for them regardless. You might live in some science fiction world where energy and automation were so abundant that manufacturing sand from something other material and shipping it in made economic sense.
cost = energy-intensive manufacturing + lots of shipping
It wouldn't prevent this crime because it's never going to be as cheap as going to the river and filling up a truck.
cost = a short drive + a few bribes
Technology is absolutely not the solution to everything (although sometimes it helps a lot).
The article mentions, among other things, thieves who steal sand, sell it, and bribe police to look the other way. While that's the state of affairs, lowering the cost of energy is beside the point.