Designed so they wouldn’t become another HDMI fiasco, where you have to search for aftermarket clips so your plug stays in. Now, do Displayports need it, probably not. They feel about as secure as a USB. But there is that fear going back to even VGA, where most worked fine without screwing them in, but just to make sure… (I can’t recall, did EGA have screws?)
Designed so they wouldn’t become another HDMI fiasco, where you have to search for aftermarket clips so your plug stays in. Now, do Displayports need it, probably not. They feel about as secure as a USB. But there is that fear going back to even VGA, where most worked fine without screwing them in, but just to make sure… (I can’t recall, did EGA have screws?)
I think all of the serial style connectors did, but some were considered optional in the spec.