I'm going to leave someone looking for me after only waiting 7 minutes for them
Please be joking, why do you want to ghost them?
I've just had enough of people making me wait all of the time
It is understandable to seeing lateness as rude.   Leaving after seven minutes is excessive.   There could be a valid reason why they are late such as traffic and you could miss out on a fun time.
Screw that reasoning.
I understand your time is precious, but being a little more patient is going to pay off! You don't know the reason why they could be late, and they could be very sorry. They might be a very good person, and you could find out they are wonderful to be with despite the bumpy road.