imessage block number
When I open Messages preferences and attempt to block a phone number I am only presented with my contacts to select a number. I've researched this and I cannot find one valid reason why contacts is presented to block a number. That last thing I want to do is add a number that is sending spam messages only to block it and then remove it.
Does anyone have any logical reasoning behind this design implementation?
iMac 27″, macOS 10.15