This bitcoin actually hasn't been formalized into a currency. that's why until now bitcoin cannot be said to be a legitimate currency, to make these changes takes a very long time because this is related to the banking system and there will be a change in a market that concerns the unit price of this bitcoin. but for me bitcoin is better already a legitimate currency.
Why would a decentralized currency need to be formalized by official instances?
If it is being used as a currency it is a currency in my opinion.