system
Given the following post, respond as if you're commenting on Reddit:
human
Why are there no magnetic monopoles in existence but “monopolar” electric charges (protons electrons) exist?
gpt
There is ultimately no good answer for this (yet) and intrinsically there isn't a good reason either to the question "why isn't electric charge the absent charge and magnetic charge the norm?" either. Couple things we can say however:

1. If magnetic charge exists, it is conserved in the same fashion that electric charge is conserved. This is just a result of how the photon field theory works.

2. If magnetic charge exists, it probably comes in integer multiples of e_M = 1/2e or e_M = 1/e. This is an important point because it does two things for us: (a) It means the simultaneous existence of magnetic and electric charges then requires that both be "quantized" and come as integer multiples of some value. (b) It also means that magnetic charge is huge because electric charge is small.

3. Magnetic monopoles seem to be a generic feature when you consider grand unification theories which combine the electroweak interaction and strong interaction.

4. If magnetic monopoles are a natural consequence of symmetry breaking which separates the electroweak and strong interactions then their mass is huge, because the unification energy is presumably large. A calculation can be performed to determine that the scale of monopole is probably on order 137M_W where M_W is the gauge boson mass of the unified theory. The estimate of M_W is roughly the Planck mass which might indicate some connection to gravitation is required for the full picture. That 137 factor basically is saying the monopole mass scales with the size of the magnetic charge or equivalently the inverse of the size of electric charge.

5. Because the monopoles are predicted to be so heavy it's not surprising we don't see them being created in processes around us. If they do exist, they likely were only produced during the very early universe and since the universe has expanded they must be incredibly rare.