I notice some models of cameras include a hotshoe cover as standard. But many other brands don't.

And they are available to buy as accessories, from about $1 on Ebay for a basic plastic cover. Or up to $30 for a shiny steel or wooden cover.
But is a hotshoe cover useful? What does it actually protect the hotshoe from? Is an uncovered hotshoe likely to get damaged, in regular use of the camera?
Or is the cover just for decoration, to make the camera look nicer, or add a bit of bling?