Opposite experience for me. After I had kids, I realized how shitty and neglectful my parents had been. They kept me alive but they otherwise didn’t do much. They were more like roommates than parents.
That will depend very much on the individual. Someone who were beaten by their parents won’t suddenly turn around and love them when they themselves get children.
After having one (1), I realized that my “shitty parents” were actually amazing superhumans, despite all their very human flaws.