Many industries and construction industries can use sand, which needs to be angular. If the sand is too smooth, it is not suitable. But now the sand in the desert and the sand by the sea are too small and very smooth. In fact, when you step on the beach barefoot, you can feel that these sands are not suitable for building.
At the same time, deserts are generally very far from cities. Even if sand can be used, the transportation cost may be much higher than the cost of sand. Economically speaking, it is not suitable for architecture. So basically, the sand in the desert can't be put into industry.
Then after removing the sand from the desert, there is actually very little sand to be used. Most of the available sand resources are actually river sand salvaged from the river. But now because people's living areas are getting wider and wider, the area of rivers is getting less and less, and river sand is not so easy to regenerate. In recent years, people have been developing and building houses, which consumes a lot of river sand, so there are not many available now.
So now that there is a shortage of sand, it mainly refers to the amount of river sand. Although river sand is also a renewable resource, the speed of regeneration is still very slow. In addition, the area of rivers is also decreasing, so the available river sand is indeed decreasing. Of course, this has a lot to do with people's constant destruction of the environment.