Imagine you are told you have cancer which could get treated. You are given two options:
Option 1 is a 10/10 rated Health Service which will give you the best possible care. The problem is there is 20% chance you might not qualify for this service and will receive very little care, and 80% chance you will qualify and receive the best care. You can't change your mind after you have chose this option.
Option 2 is a 8/10 rated Health Service which will give you very decent care. There is a 100% chance you will qualify for this service, it's available to everyone and there's no risk involved.
Option 3: Cook some meth.