There are many reasons why China air gun are not widely available in the market. The first reason is that air guns are not powerful enough compared to other guns. Second, most air guns are sturdier than other guns. Most guns can withstand the high temperature and pressure generated by each shot, but the air gun cannot do this. It has more moving parts, so it is more prone to wear. For example, the springs of air guns, bushes and washers that increase air defense capabilities are very easy to wear.
The caliber of most air guns on the market will be much smaller than that of ordinary firearms. The smaller the caliber, the smaller the power to advance the projectile and the air gun will also be more practical.
Earlier air guns in history usually only had a single shot, and each shot needed to be lifted. The inability to shoot multiple shots was also one of the reasons why it was inferior to ordinary firearms.
However, air guns are generally cheaper and easier to obtain, and the cost per shot is much lower than firearms. Air guns can also be used indoors and in many places where firearms are not allowed.
In modern society, the scope of use of air guns is also wider. Modern air guns are usually equipped with magazines that can hold multiple bullets, which means that the air gun can shoot faster. Moreover, the compressed air gun that pushes the shot is almost silent. The smaller caliber also means that the air gun has stronger destructive power, faster speed and higher accuracy. This all depends on the advent of air compressor.