I think Gemini did better than you think with its second answer! Your original question didn't mention that the bags were made of the same material or the same density of material. The set of all possible bags that could hold 1 pound of feathers includes some thinner, weaker bags than the set of all possible bags that could hold 1 pound of gold (the gold being denser). So absent any other prior information the probability is greater than 50% that the gold-bag would be heavier than the feather-bag on that basis.
One could go further into the linguistic nuance of saying "this can hold one pound of [substance]", which often implies that that's its maximum carrying capacity; this would actually make the "trick question" answer all the more correct, as a bag that is on the cusp of ripping when holding one pound of feathers would almost certainly rip when holding one pound of (much denser) gold.
Saran wrap would would a pound of gold. It's just a pound in roughly a cubic inch of material. A cloth bag (like a pillow which is how features are normally contained) would definitely suffice. Remember, a pound of 800 fill down would require 8 cubic feet.
The bag for the gold doesn't need anything substantial.
So, no, the chances are strongly on the side of the feather bag being heavier.
One could go further into the linguistic nuance of saying "this can hold one pound of [substance]", which often implies that that's its maximum carrying capacity; this would actually make the "trick question" answer all the more correct, as a bag that is on the cusp of ripping when holding one pound of feathers would almost certainly rip when holding one pound of (much denser) gold.