An emergency fund helps prevent a surprise from forcing you to borrow more or sell investments at a bad time. As an educational reference, 6 months is often a prudent base. If your income is variable, you support family, or you run your own business, moving closer to 12 months gives more margin.
A debt can look reasonable because of rate or purpose, but become fragile if it consumes too much monthly cash flow, reduces liquidity, or blocks a margin of safety.
The point is not to label debt as good or bad by name. The point is to look at rate, cash flow, liquidity and fragility.
This tool is educational. It does not replace financial, legal, tax, or insolvency advice.