I believe that one of the main reasons why every child both parents is to grow up to learn from both of them. Each parenthas roles they can only play and can o my play it perfect. A father, no matter how perfect and emotional intelligent he is will not be able to do certain things a mother should do. Not that a father would not try to but it just can never be like that of a mother: same thing for a mother, she can't do certain things for a child that is suppose to be done by a father. Some roles are best played by a father or mother: a single parent can only try to cover up. It can be a lot, tiring, overwhelming sometimes when one parent, either mother or father is doing the work of two people because the other isn't available.
For a single father. It will take more than just masculinity, provision of needs and protection to raise children. A single father will have to learn or improve his emotional intelligence and expression to manage his family well, he will have to be a mother to his child(ren) even as a father. He has to be more caring and affectionate to and around his children: validating their emotions not correcting or shutting their emotions up. The effect of a single father being just a father are these; the children will only and may interpret love, care, emotions, reason and understand based one how the father was, what they have learnt from their father, what they have seen him do, hear him say.
It's almost the same for a single mother. The children will learn much more of whatever a mother can teach and instill in a child, but they will not have the first hand experience and knowledge of what a father is and the things that they ought to learn from a father. A mother will only be able to do what a mother can do and do the part of a father that her capacity allows. Children from singe mother tends to be a bit soft and emotional than because they don't have a father, but other cases they could also be very resilient because the single mother tried to be a father to them.
The effects I mentioned might not be true in all cases but they do happen. There are cases where the children of either a single mother or father grew up so well like they had two parents: which was a result of the single parent covering up for the missing parent. However, a single mother or father from a failed marriage might want to pass their trauma or experience to their children, training them based on their experiences which might not be a balanced. For example, a single mother from a result n of bad marriage might always want to advice the daughter to never trust man, men aren't to be taken seriously, etc. Likewise a single dad might also want to pass his trauma as an advice to his son(s) e.g women are after money alone, women only pretends tl they get what they want,etc.
Certain knowledge are best taught and learnt from experience: having a first hand experience of some things will give better understanding. So, a child raised by one parent would still lack (might be little) some basic knowledge that should have been learnt from the missing parent. Parenting is not an easy thing to do, it demands so much time, resources, wisdom and understanding to be a good one.