Question

Why magnetic monopole does not exist?

Answer 1

Magnetic monopoles do not exist. If you slice a magnet in half, you get
two smaller magnets. On the other hand, isolated positive and negative
charges exist. There exists a smallest unit of charge, for example, the
electronic charge with value |e| = 1.6 ×10–19 C. All other charges are
integral multiples of this smallest unit charge. In other words, charge is
quantised. We do not know why magnetic monopoles do not exist or why electric charge is quantised !

Answer 2

Magnetic monopoles do not exist however it is theorized that they should based on quantum and particle theory. Many researchers are running experiments to find them.