The Swedes have a high single mother rate and because of good education and social services, their country is fine.
The Arabs have litters of children, much like dogs (for the Arabs fix it so they never use protection). The men don't literally take care of all their children (or any) They leave that to the women and fukk prostitutes on their downtime. All, both rich and poor, do this. For the poor, the children mostly remain poor. For the rich, the children mostly remain rich. As such it is not the number of children which matter but something else.
It looks to me like the problem is not single mothers or lots of children. It is more to do with how the children are raised. You'll notice the children of that black guy with 25 kids look neat, healthy and well-adjusted.
Let the black man have as many children as he pleases, with or without marriage. Such is his right.