Outside dryer vent clogs with lint
Your parents did not have a screen at the exhaust vent terminal either. Somebody installed the wrong type of vent cap on the dryer vent.  Dryers are particularly dependent on much free flowing air for proper operation.  All dryer exhaust air is full of fabric lint. Fabric Lint will always clog a screen.  Either replace the existing cap with the right one, (screen free) or jerk the screen out of that thing and live happily ever after!