Are you saying that defective Navi 32 and 33 chips land in the bin? It sounds excessive to me when they could just make a 7700 non-XT, or a 7500 XT instead, and still make some money on them.
Whenever AMD (or the others) develop a new chip they assess the first batch of production wafers to segment the chips into various product tiers, including desktop parts, mobile parts, enterprise parts, special OEM parts, and possibly special tiers for single customers. All of these will be various bins, including the ones which are not yet intended for a product. And the very last bin will of course be discarded chips. AMD have some flexibility in deciding how many tiers they want, but too few tiers will result in large variation inside a single bin, and the resulting product will have to be specced based on the minimum requirement of the bin. As yeids improve, the bins might also change, and we often get product refreshes. Still, there will usually be various bins of semi-functioning dies.
And here comes the point; the more wafers you run, the more chips will be in each bin, resulting in higher potential to turn them into products.
I.e. if 0.5% of dies are having large defects on otherwise good chips, then making 100,000 vs. 1,000,000 of these chips would result in 500 vs 5,000 in the bin. As Nvidia produces much more chips than AMD, they have lots of more options of using these bins. But AMD does it too, including OEM only products or chips for custom products you've never heard of.
