Some people come to learn that it can be quite conditional between parent and child as well.

Even that can be conditional. Parents deliberately remove themselves from their children's lives sometimes for various reasons. Child is gay/trans or othered in some other way. Child commits some serious crime, etc.

It could also be the parent is too much of a mess(drug addict, etc) that they can't love their child.

And only some at that. Mine only "loved" me if it made them look good.

The number of parents I have seen disinherit their children for something that literally is equivalent (and actually once was) "when they moved out when they were 18 they didn't clean up their room enough" is in the dozens, there's no such thing as unconditional anything in this world.

Maybe only parent-child can be unconditional, but it doesn't imply ALL parent-child love is unconditional though