This as a childfree (and, admittedly, terrified of my parents asking for this at some point) person I often ruminate on and struggle with.
Do we really owe our parents anything if we didn't choose to exist? Like...if we slow down and pick apart the immediate reaction of 'that's so cold!' or the assumption of nobility in the choice to have a child... hmmm.
It's a tough and interesting question that I'm starting to delve into with my parents, as someone who struggles immensely with caregiving and the emotional pain it causes.