Jade plants have a very fine fibrous root system that doesn't squeeze itself out. The roots of woody plants continue to get thicker and thicker and can literally cut the trunk at the base and kill the plant. Grasses and other monocots have roots that never increase in diameter so they don't get rootbound.
Yes, the roots can still function as long as they can continue to create root hairs at the tip of the root which is where all the absorbing occurs.
