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human
ELI5: Why do electrical plugs with two prongs have a certain orientation for a socket in lieu of making them symmetrical?

I was plugging in my blow dryer this afternoon and I noticed it.
gpt
Electrical outlets are typically set up (in the US) with a “hot” side (carrying the actual voltage) and a neutral side (which is essentially no voltage and the same as ground)

The third pin (if present) is also ground and 0 volts. However, the “polarized” plugs you’re referring to won’t have this pin. The blade width difference is to control which wire of the two carries the actual power. (Old-school plugs have blades the same size)

It is typical for manufacturers to tie the neutral to the chassis of the device to save on wiring costs (for two-wire devices). The danger is if the chassis is “hot” “ as a result of flipping the plug - you could get a shock just by having your body in between  the device and any ground channel (I.e. a plumbing fixture). 

The narrow blade of the plug is specified to be the “hot” in this case; and allows users and manufacturers to consistently ensure the connection is made without energizing the chassis.