All my friends are guilty of this shit one way or another, but there's one particular "friend" of mine who is chronically late to everything. Not being exactly on time, sure. Nobody's going to hold a grudge over the fact there was a 12 car pileup and traffic is actually moving backwards. But when you're late every single time, to every single thing. When you are incapable of telling people estimated time of arrivals, and especially when you don't then inform them of when and why you are late, or even if you are coming, that's incredibly fucking rude and malicious. And no, I really don't care about "Oh I have time blindness" or whatever.
I don't mind if getting ready or transporting is really difficult and time-consuming. Arriving somewhere at a late time is far, far less egregious than saying you'll arrive at a place at one time, and arriving at another. If you say you can't get to a place till 10 pm, that's fine, as long as you say that. But if you insist you'll be there at eight, and don't, and then fail to inform as to an estimated time and why, then you clearly don't respect other people's limited time on this Earth. And it's especially baffling to be late to something online, while you are at your house, when you have nothing else to do but this.
If you do have some reason why you cannot possibly help but late to everything you ever have to do socially, then its up to you to mitigate that, not on everyone else to shake off your chronic inability to realise that other people exist and have places to be and things to do. At the very, very fucking least, keep the people you're meeting informed. Apologise before you get there. At least pretend you care about other people.