As much as he may try, a dad may have a hard time convincing a court to award him either legal or physical custody, and he may be left with getting some parenting time with his child.
It may be that the dad has just recently come back in to the child's life or is just getting started with building a relationship with his child. In other cases, the father may be struggling under the weight of an addition, a criminal past or a mental health condition that makes it hard for him to make a convincing argument for custody.
These dads should remember, though, that even if they do not have decision-making authority, they still have some rights to access their child's school, medical and other records. The other parent may not prevent this and in fact should facilitate the process if they need to do so.
A dad will likely need to establish legal paternity in order to have this right, and there are certain limited exceptions to this right. For instance, if the child's mother is claiming to be a victim of a domestic violence, it may make it more difficult for the man to obtain his child's records since they could include the mother's address.
In any event, among fathers' rights is the right to have reasonable access to information about his child, as he ought to know how the child is doing at school or how the child's overall health and treatment are progressing. It may be necessary to get a court order or ask the court to enforce an existing order should the mother not grant the father access to information voluntarily.