See subject line. Dictionary says the verb has the same etymology as the noun referring to wool. So how do we get from sheep’s wool to ripping someone off?
Ever see a shaved sheep?
I suppose that after a shearing a sheep is left substantially reduced and looking a little foolish.
Yeah, it’s just a very specific metaphor for “taken for everything you had.” Think about those old-style cartoons of someone so destitute they’re left with only a wooden barrel on suspenders, which is just modest comic strip shorthand for “they even took my underwear.”
You can shear the same sheep time and again, with some planning.
“To fleece” goes back to the 1500’s to mean what others have provided.