It can run down your rain pants and still get your feet wet. Rain pants and gaiters are about the best you can do. If it is a downpour, your feet will still get wet unless you have some sort of waterproof shoes. A brushy trail will get you soaked too. No free lunch!
Slogging around in cold rain all day on a shoulder season day hike needs the whole kit-- ventilated parka, pants, gaiters and waterproof/breathable shoes. My trick is to wear wicking long johns under rain pants for all day wet hiking, keeping me warm, dry, and the cold fabric off my skin. Adjust the thickness/weight of the base layer to suit the temperature and activity level.
A summer shower is bearable. I carry a poncho for summer stuff-- it ventilates and keeps my pack dry as well as providing emergency shelter. As with the stream crossing issues, shoes that breathe and dry quickly are the best bet. Having to stop and take things on and off and deal with wet muddy stuff is a pain. If you want use a poncho, consider rain chaps as a light option.