I live in Tennessee and I understand state law requires that everyone who owns a car or truck have liability insurance coverage on the vehicle. Why should I spend money to purchase uninsured motorist insurance coverage if everyone already has liabilty insurance?
Because (a) some people don’t follow the law; (b) some people buy liability insurance coverage but do not purchase an amount that will protect you from losses you sustain in a car or truck wreck; and (c) you may get hit by a hit-and-run driver (and unisured motorist coverage gives you some protection in such cases).
Despite the law that mandates insurance coverage, 20% of the people in Tennessee have no insurance on their vehicle. That means that 1/5th of the people you meet on the highway have virtually no way of meeting their financial obligation to you if they cause an accident and you are hurt. You need uninsured motorist coverage to protect you from that risk.