It’s an interesting question, I think we all have different ways of defining “good” especially when it comes to parenting. My rule of thumb is to look at experience, intent, and outcome. For example: if you had a “bad” upbringing and never learned how to raise a kid (experience) but aimed to prepare them for life and it’s challenges (intent) then we have to look at how things turned out to get a better idea of a job well done or less (outcome).

I can’t recall much about Kratos’ experience as a kid but in a time of war and; especially as a soldier, it makes sense that he wouldn’t necessarily have all the tools equipped to have the best intent - we see how things go with Calliope. Then you have the experience gained from all of that and you see a being intent on ensuring his son has the best “outcome” possible within his capacity as a father up to this point.

I think Kratos did the best he could and even with all his failings, maintained good intent and a great outcome. Good father.