I think it's been done before, albeit unsuccessfully. How, logistically, would a small dev team manage something like that? You could only really trust a public company to offer a commodity-backed crypto.
It also turns a decentralised, trustless cryptocurrency into something that is centralised and requires you to trust the entity that holds the underlying goods.
Historically, this has never worked out for anyone.
Except when banks did it in the early 20th century, but yes, it does centralise the currency.
You could do it by offering an exchange service that allows you to trade the coins in for x amount of commodity. This would work. provided you offered the right amount of commodity, i.e. not so high that it all gets dumped.
You could use the premine to buy the commodity, then divide it amongst the remaining coins that will ever exist. It would set the coin's floor, at least.
