Frog lungs are poorly developed. How does this relate to their skin being thin and moist

It relates to it because the frogs can breathe through their skins. We can too but it's not developed because we don't need it, but skin has pores for perspiration as well and transpiration. Frogs however don't have developed lungs like we do so they get a lot of the oxygen using their skins because they had to develop this system or they would not exist today.