The biggest problem with Bitcoin is that it has no physical form — it is entirely digital. Without electricity and internet access, it cannot be used at all. For small retail purchases or in emergencies, where cash can be instantly exchanged, Bitcoin is impractical. Additionally, elderly or physically challenged individuals, and those unfamiliar with technology, would face significant difficulties using it. On top of that, Bitcoin’s extreme price volatility makes it unsuitable for stable day-to-day transactions. For these reasons, fully replacing fiat currency with Bitcoin is highly impractical in reality.