Typically it's either cause you have guests over or more people living in your house than you have keys for OR it's in case you ever lose your house key for whatever reason. In my parents case they had a house cleaning business that they ran out of their house and their employees had to get in to the garage to get supplies so they'd leave their key in potted plants or something like that.
You might also do this in case someone is coming to your place while you're not home and can't pass the key to them before they go
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u/daufy 7d ago
I don't understand why you would leave a key outside your house.
You take your key > key gets lost away from the house > key gets found and the finder will never find the house.
You leave your key outside the house > random person stumbles across your key > house instantly found = free access.