Ever chucked a huge chunk of sugar block into water? note how its extremely slow to dissolve?

Same with food, the more you chew, the smaller the food bits become, this overall increases the total area your stomach acid can interact with the food.

When you don't chew, and just swallow an entire brisket full, it will take a long time and too much energy for the body to process, and in turn, decide that it's not worth the effort/energy and just pass it out.