When they’re late, they’re careless. When you’re late, it was traffic. Notice the pattern?

Your own lateness arrives with reasons attached and everyone else’s arrives bare, which quietly produces two standards nobody ever agreed to. You have your circumstances and only their behavior, so one reads as situation and the other as character. Almost everybody does this and almost nobody notices it happening.

Try granting the assumption you would want for yourself. When somebody is late, picture the version where something went wrong for them, because it is true more often than not. Then, separately, stop offering your own traffic report and simply apologize.