I was thinking today I see two premises:
Everyone has a different perspective
All perspectives are valid
Your choice of the word, "valid" is an interesting one. Valid does tend to be used interchangeably with "true," but in formal logic and argument, they are not the same thing. Validity is a necessary condition for a true argument, but not a sufficient condition. A person can have a perfectly valid argument where the conclusion(s) follow(s) from the premise(s), but still be wrong.
In addition, you used the word perspective, which is another term loaded with multiple meanings. I'm assuming that you mean it in the sense of a point of view, a context for evaluating and synthesizing beliefs, opinion and experiences.
I'm not sure I agree with a statement that I understand to mean, "All points of view are equally reliable measures by which to assess reality." Because validity, as I said, is not a sufficient indicator of truth.