The reason why dogs can be leaders is because they have an innate desire to be leaders. Dogs are social animals and they like to gain recognition and status in a group. In a dog group, there is usually one dog who becomes the leader and is responsible for maintaining order and safety of the entire group. This dog will typically display stronger leadership skills, better protect the group from threats, and help maintain the balance of the group.
However, dogs are not humans, so they don't really "be the leader". They simply gain a certain status and respect within the group and take the lead when necessary. If your dog exhibits leader characteristics at home, you can help him adjust to family life through training and nurturing, while also making sure he doesn't pose a threat or attack to other family members.