Why have we not drilled or mined deeper into earth ? ? someone me in this ❤️❤️

Scientists have determined that the center of the earth is 6371 km below the surface. But how has this been determined? Many people might answer that question by saying scientists can drill into the Earth with machines. However, the drilling rigs that scientists use can only drill about 20 km in the Earth which is not very deep! In other words, we can only drill into upper part of the crust of the earth. Extremely high temperatures and pressures within the Earth make drilling into it very difficult

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.