first problem is that the o-rings dry out, and the refrigerant escapes.
once that happens, the system gets ruined because air and moisture make it inside.
Most people don't realize, the refrigerant lubricates the entire system, and it must be used regularly, or it will fail.
Think about the refrigerator in your house, literally the same system, and they will work flawlessly for decades, since they're always running.