"By that measure every single thing that exists is exactly identical to everything else."
Where do you get this idea? "X is ultimately just a big collection of fundamental particles" and "Y is ultimately just a big collection of fundamental particles" does not imply "X is identical to Y".
It's like saying you should never call anybody a "person" because you're implying all people are identical. I mean, what?
"By that measure every single thing that exists is exactly identical to everything else."
Where do you get this idea? "X is ultimately just a big collection of fundamental particles" and "Y is ultimately just a big collection of fundamental particles" does not imply "X is identical to Y".
It's like saying you should never call anybody a "person" because you're implying all people are identical. I mean, what?