soymilk : explained very well how lateness can be a control thing. My Mother-In-Law has (undiagnosed) NPD, and used being late to control people and/or situations and/or to make people anxious/stressed. There was also definitely an attitiude of her time being more valuable than anyone else’s. She particularly did this with people (like me) that she didn’t like and wanted to ‘test’ in some way. On one occasion, for example, I had booked, and paid for, timed tickets to an event, and she was 40 minutes late meeting me, meaning we very nearly didn’t make it. Another time she was an hour late, leaving me waiting with heavy bags outside in the heat. She would also always be late for restaurant reservations, etc, and always took ages getting ready.
I tend to think that if people are habitually late, at the best they lack manners and respect. I don’t think being disorganised is an excuse for habitual lateness, particularly when the indiviudal (like yourself, OP) recognises that there is an issue. If you know you frequently run late, why not then aim to be somewhere 30 minytes before you need to, to allow for slippage? Why not work on being more organised, and not keeping people waiting?
And at worst, yes, it can be used as a means of control or manipulation. When my Mother-In-Law was late, as in situations I’ve described, it would cause me unnecessary stress and anxiety (will we actually get in, or will I have wasted money, etc).
By the time of our wedding I was wise to her and how to deal with it, and both her and Brother-In-Law (who was taking her to the venue) were told exactly what time family photos were happening, and that if they were not there, there would not be another opportunity to have those photos taken; and you can bet we’d have followed through. If someone is using lateness as a control thing, then as PPs have said, that’s the best way to handle it: you continue with your original plans and if that means they miss out, tough. So, how I should have handled the previous situations would have been to say ‘sorry Mother-In-Law, but I’m going to leave now to make sure I’m there on time; if you manage to make it, I’ll see you inside the venue’.