system
Given the following post, respond as if you're commenting on Reddit:
human
[Pokemon] Explain every type weakness/resistance

Some are obvious, like water putting out fire. But how is Bug strong against Dark?
gpt
Normal is mundane animal life- easy prey to trained humans and stone tools, and with no ability to interact with the spiritual world.

Fire is straightforwardly extinguished by water, sand and stone. Meanwhile, dragons are the masters of fire and have no fear of burning themselves

Water conducts electricity- a bad idea for a watery being with organs- and are drunk by plants. Dragons are as associated with water as fire, and seem to hold dominion here too.

Fighting is purely physical. They've got no counter for the esoteric powers of faeries, psychics or ghosts and on a simpler level, birds and bugs are too fast to hit. Meanwhile, their dependence on physical perfection makes anything that ruined their health a devastating blow.

Flying creatures have thin bones, easily broken by rocks and metal.  Also being in the sky among the clouds, things that can influence icy winds or lightning find them easy targets.

Grass is plant matter- it burns and is eaten by bugs or birds all the time, and easily dies in the cold. The same thirst that makes it so potent against water betrays it here, hungrily absorbing poison.

Poison depends on poisoning its enemies, obviously. Psychics and ghosts have transcended their physical bodies while dirt, rocks and metal simply have no biological functions to disrupt

Electricity is grounded easily- the charge simply dissipates too far, which also protects plants. Meanwhile, electrical enemies constantly have strong current running through them- a few hundred volts more is barely noticeable.

Psychics require focus to use their powers- primal fears like insects, ghosts and the dark shatter that concentration. While their mind powers are potent a fellow psychic can resist them, and a machine's mind cannot be swayed.

Ground is hard to change on a large scale but water, icecaps and forests alike can reshape it on even the scales it works on. Bugs are the opposite- simply too small for the ground to notice meaningfully. Birds are move obvious- they're in the air and it can't reach them.

Rock is not as tough as it seems. Breaking rocks with their bare hands is a party trick for fighters, and ice, grass and water break them down quickly. Meanwhile, metal is simply stronger- in a brute force contest, steel wins.

Ice melts, but is also more fragile then rock or steel and easy enough to break with brute strength. Meanwhile, all it can do to water is freeze it, and that's not really harming it, is it?

Dragon is slain by another dragon, or a knights steel, or a fairyland enchantment. More mundanely, magical or not, they're reptiles, and cold-blooded beings do poorly in the cold.

Dark is the "villain" type- it's lies, backstabbing and manipulation, dirty tricks and clever plans. Insects are too stupid to fool while warriors are too blunt to care. Meanwhile, faeries have plenty of experience with lies and manipulation themselves- can't con a con.

Ghost is a type of victims and tragedy, giving it an inherent weakness to those dark of heart- they already lost to them once. Meanwhile, their intangibility is no protection to those equally spectral.

Steel is hard to destroy with brute force. But fire can soften it, a skilled fighter can see the weak points, and the sheer size of the earth dwarfs it. It also conducts electricity, and how do you hurt an enemy that can hide in your arms?

Fairies weakness to iron is well known, as is their weakness to drink and hedonism making it easy to get them to consume something deadly. Meanwhile, as things of whim and chaos, fire's nature as a representation of order and civilization drives them away.