I agree an objective viewpoint is possible to find, but any conversation about "America being over" needs to start with confirmation that the speakers have agreed upon an objective viewpoint.

Decontextualized, the fundamental rights Americans celebrate are at odds with each other (right to life and right to liberty are the obvious examples, and some good criteria for discerning how to maintain those in coexistence has been established, but others, like "Freedom from fear" or "Freedom from want" and "Right to liberty," are much, much murkier. And this is all, of course, in the context of an ever-changing world that brings new technologies and experiences that must be interpreted against those rights).