Only for a very short time. The playpen is safe, but it limits the possibilities of getting to know the world. In some families, the playpen becomes an indispensable prop, when there is a small child in the house. It is a safe place for him. A baby of several months is usually placed in this string or rung cage. And you wouldn't be bored, some of his toys are also thrown in there.
During this time, parents can go about their business. The first year of life, however, is characterized by, among others. great need to make discoveries, explore the world. So the ability to crawl is useful. You have to help the child in his efforts.
Closing it in a playpen protects the baby from danger (will not put a finger to the contact), but it deprives him of the explorer's joy. Therefore, let us treat this solution as a necessary evil. For example. only then, when we prepare dinner, and there is no one to look after the child.