I am not a single dad. But I have observed some.
Consider two sons of my spouse:
The older one has two daughters and he owes child support money which he has ignored, but that's still out there in the legal system so he can't get a driver's license. That guy is like a giant boy.
The younger son is from a different father, who was Black. He is very, VERY attentive to and protective of his two children. Don't get between the lion and the cubs. I respect him for that.
Another thing about children is, they are a story not yet told. What is their future, what will they become? We as adults can show example and offer education. I could very easily be the grouchy old man, but I don't do that. "Just smile and wave, smile and wave."
There are so many opportunities to be a teacher. When you are an adult and children regard you in awe, then you have the responsibility to educate them. Maybe it's how to cook in the kitchen, or dig in the garden.
Anyway, I salute the single fathers for taking responsibility. Some just walk away.