What does it mean if you don't pay back a loan but your credit score isn't dropping?

The scenario is this:

1. Someone took out a $5,000 loan in January of 2024
2. The person paid about off of it back until mid year of 2024
3. The person blocked all payments for the loan
4. The person's credit score hasn't dropped at all. Also, it doesn't say on credit reports that the person missed a payment or has a defaulted loan

What does this mean?