I highlighted your last sentence, because it is a good one. But you also say:
“…Much like everyone else on Earth, Shapiro’s reasoning fails at the same limitations as the rest of us…”
The big destructive philosophy of our times is that there isn’t a “truth” at all on anything, and hence there isn’t even relative “closeness or remoteness from the truth” on the part of any intellectual position. But those using this argument are always selective in their application of it; generally it is used as an escape clause for avoidance of accepting the truth, or accepting that someone is just plain “correct”, period. One cannot use facts or evidence, so “relativism” is the escape clause.
They can’t honestly believe that the most obviously absurd beliefs are “equally valid”; this is just a bad-faith trick to weaken the value of the obviously true. Theodore Dalrymple insightfully says that making people assent to and “believe in” obvious untruths, is the most effective means of destroying their ability to think and judge; Orwell’s tale of 2+2 equaling five, is the whole point. Hence the lack of scientific advance in absurd theocratic systems.
But even the relativist position itself, must be invalid under its own criteria.
David Horowitz concluded one of his books with a statement that has seared itself into my memory: with just slight amendment over time on my part, here it is:
“It is impossible for reason grounded in truth, to dislodge from the human heart a lie grounded in desire”.