When compared to the JPM 'internal' coin, it is perhaps easy to understand why Iran would create a national coin.
However like the Petro, the question is what can these coins be used for?
Whilst a gold backed coin sounds good initially, like an oil backed coin, the spending power is dependent on 2 parties agreeing on that value.
With a gold backed coin, why not just send gold, at least a paper/digital version of it.
The same with oil. Creation of IOU's might work.
But given the bans imposed by the USA on these countries, who would accept the IOU's or even their crypto?
Perhaps Iran needs to follow the petro, and ignore the concept of a national crypto, and just accept the globally accepted BTC. or if they are concerned about security perhaps Monero.
But both of these national coins seem to be as useful as an internal JPM coin.
https://www.cryptoglobe.com/latest/2019/02/details-emerge-on-irans-xlm-based-gold-backed-crypto/