Crypto back by something tangible rather than work product related is required to establish a 'money' function for the blockchain.
Several countries have looked at oil, others gas or other natural resources.
But a common & well established basis for any currency has always been gold, until recent history.
Hopefully one coin will make this a reality in the near future.
https://beincrypto.com/paxos-launching-yet-another-gold-backed-cryptocurrency/