There is the chance you don't get to do the transit security. A certain number of planes per day from origins that are assessed to be secure enough are randomly selected to bypass transit security.

You're unlikely to get this treatment from an apron/bus gate, but if your plane parks at an air bridge then if you don't have an escalator taking you a couple of floors upstairs once you get off the slope of the air bridge and you walk out into the terminal you've just won the no transit security lottery that day.