if measuring things in dollars is an illusion,
what reliable measurement are you using to measure % return of gold?
Discussion
The unit of an account doesn't have a return, by definition. It is the benchmark used to measure all other goods.
That is a non sequitur.
You are using USD denominated value to measure % return on gold
while simultaneously asserting the USD denominator is meaningless.
Your OP is self contradictory.
Definition: A non sequitur is a statement, conclusion, or remark that does not logically follow from the preceding statements or premise.
All I'm trying to say is that a "gain" depends on what you measure it against. I dont think that is a non sequitur.