Not necessarily bro, it's very fine to keep it in a financial system that doesn't experience much volatility, it would've been best in Bitcoin but the volatility is a great problem now.
For people with currencies that crashes against the dollar, they can keep them in stable coins like USDT to reduce the impact of inflation on it or you can even place it in the save option in a microfinance Bank app so it's there getting you little profits while you can break it anytime emergency comes.
If you convert your emergency fund into Bitcoin or buy Bitcoin with the money from your emergency fund. If an emergency situation arises, do you mean that you will sell that Bitcoin to deal with the emergency situation? If you mean something like that, then this is a completely wrong decision. Because suppose you have bought Bitcoin with your emergency fund money. If your financial crisis shows up and the Bitcoin market falls. Then where will you get the money to deal with the financial disaster? For all these reasons, it is never right to keep an emergency fund anywhere, it is always better to keep an emergency fund in cash.