Why can't my world trigger chain mining

First of all, mining is usually done in the mine tunnel, and the efficiency of mining in the mine tunnel is also very high, because the minerals are exposed. But the size of the mine is limited, so we can wait until the mine is finished to develop the artificial mine. There are many ways to develop artificial mines, such as digging vertically down, or two grids straight ahead, which are all very common mining methods. However, these mining methods also have many loopholes. For example, when digging vertically down, if magma is encountered, it will die. This is a very fatal problem, although it can be avoided by digging straight ahead, But when you dig straight ahead, you will lose a lot of minerals and so on. The rule of mineral generation in my world is that the minerals generated will not be connected together, but scattered. Therefore, if straight-line mining is used, there will be ore leakage, while fishbone mining is scattered, so the efficiency is obviously higher than other mining methods