that would be better than any kind of items being tradeable for sure.
and i doubt blizzard would make legendary, unique or high tier items tradeable anyway considering their stance on the matter. which is a good thing.
even “sacred” and “ancestral” i doubt they’ll be tradeable considering they are a higher tier of item that regular rare.
but comestic as trade , for blizzard , it’s the less likely scenario : there will be botting and rmt for…cosmetics.
and cosmetics are buyable in diablo’s 4 cash shop.
consdering how it would affect blizzard money directly if players would sell cosmetics for cheaper than the actual in-game store…well they might despise that the MOST (even though it doesn’t change a thing for player and could actually be something actually ok as it doesn’t impact power balance in any pay to win manner contrary to actual items )
unless it’s only for comestic not buyable through the shop, then , they might approve of it.
(funny though how their reaction to your idea shows that they simply want things to RMT with, whatever it is…)