Why do guys make plans with u and say they’re coming till the last second just to ditch you?

Like why can’t u just say ur not coming or delete/block me before I go and wait at whatever spot we’re supposed to meet at for like 30 mins just to waste my time? Sure, it’s to “waste my time”, but how do they get any fun from that? Cuz it’s not like they can see me actually being there waiting