What makes you think they are necessarily scams just to get you to divulge your bank details? The first one you get is to get up your nose so you reply with dire invective. They know you exist.
Like the old WW1 trenches joke of Tommy Atkins shouting "Fritz" across the divide and when "Fritz" (there must be one) looks over the parapet & shouts "are you calling me?" Tommy fires in that direction. There's more to the joke but I will spare you that.