Being five minutes early is free. Being five minutes late spends someone else’s time.

Arriving early costs you almost nothing and arriving late spends somebody else’s day. That lopsidedness is the whole point: your five minutes are yours to lose, but the five minutes of everyone waiting are simply gone, and people register that. Lateness is rarely read as a scheduling problem. It gets read as a statement about whose time counts.

Work out the real travel time for the thing you are always late to, add ten minutes, and treat that as your leaving time. Bring something to fill the wait. Spend your own margin instead of theirs.