If someone thanks you or apologizes and they are showing no gratitude or empathy is it still valid?

Growing up I was always taught to apologize and really mean it and I fou d either others don't apologize or they say it because they have to but they don't really care. I mean now it's gotten to the point where people do things and act like I'm too insignificant to even notice.
And if I'm honest I resent the severe punishment I endured to be "nice!".