For example, if my parents someday needed a place to stay (maybe they can't take care of themselves). I'd feel responsible for them. I definitely feel like I'd owe them that and would feel responsible for their well being.
Though, that wouldn't be unconditional. I can certainly envision a bunch of situations that would change that.
I guess what I'm saying is it's complicated to me.
I'm lucky enough to have a decent upbringing and get along with my parents as well, and this comment isn't intended to be combative, but the "You don't owe your parents anything for doing the job they signed up for" is not strictly true in a legal sense. This is a reflection of American family values enshrined in law.
[1] https://en.wikipedia.org/wiki/Filial_responsibility_laws
IMHO, no. You don't owe your parents anything for doing the job they signed up for. I have a great relationship with my parents and had a great upbringing. It's very difficult for me to imagine cutting off contact. However, I also don't feel like I owe them a single thing and I think they'd agree with me on that.