Do copper bracelets have any therapeutic benefits?

This too, is wishful thinking. It is a fallacy that has been promoted again and again down through the ages. It is mixing the appearance as objects that are truly special, as the science of metallurgy is somewhat akin to magic in creating such objects that can have a great beauty of design and appearance as well. But that does not confer supernatural powers or medicinal power. It is simply making assumptions and then having the idea spread, much as a rumor can take hold and suddenly a whole group of people will believe it. This is what has happened over the years and unfortunately has no merit.