Dryer ducts are important to maintain as lint will accumulate and potentially block them. A blocked dryer duct system is very dangerous and extremely inefficient.
As the lint will have nowhere to go, it can settle around the heating element of the dryer thus presenting a serious fire hazard.
As the duct becomes clogged, the moisture will have nowhere to go and the clothes won’t dry no matter how long the drying cycle works.
A clean and clear dryer duct/vent means safety, efficiency, and reduced energy costs.