There is a major issue which is becoming resistance in the way of Bitcoin to be accepted globally and it is its "Volatility".
In the near past we have seen Bitcoin dropping more than 15% in a matter of 3-4 hours. And there are a number of cases in the past like this.
This property is too much dangerous for any entity which is holding Bitcoin. If a company sells products/services of 10000$ and receive payment in Bitcoin, and bitcoin loses 10% in one day then basically company has lost 10% worth of their products.
Scenarios where gross profit margins of the companies are less, this property makes nearly impossible to accept payments in Bitcoin. If volatility of bitcoin is decreased in the future, it would be a major step ahead.
This is true, but only if you hold bitcoins. Companies can still use it to accept payments, but only if they develop a system that would instantly convert bitcoin to fiat. For example, instead of paying through kiosks or other methods of payment for a specific bill or service, which often includes high transaction fees depending on local banking policies, consumers could pay to a bitcoin address of the company on exact amounts, without requiring that much fee since there are no intermediary except your wallet service provider. After the transfer is complete, it would automatically convert it to fiat to prevent volatility loss.
TLDR; It can still be a mode of payment if not holded as bitcoins. Fiat would still be the basis of value, but the mode of transfer is through bitcoins (depends on $ to
BTC conversion at the moment of purchase), and then instantly converting
BTC to $, to avoid fees of banks.