You managed to pick the only "gaming" card from either Nvidia or AMD whose pricing has nothing to do with gaming. China wasn't stock piling 4090's because they were planning an epic LANfest. 4090's are very capable AI accelerators. That's why its price is so high. No one in industry has any interest in AMD's 7900XTX. When people who make money don't want your product, the price reflects it. Try comparing any other currently sold gaming cards and you won't see such a price discrepancy.
It isn't even a smart comparison if you artificially limit the scope to gaming. The 7900XTX is basically tied with the 4080 Super at 1080p, which is only $60 more. At 4k, it's only 4% faster than the 4080 Super, while trailing the 4090 by 22%. When you move to ray tracing, it's a blood bath in favor of the 4090. 7900XTX is not a direct competitor of the 4090.