My mother had her house and auto with the same agent for almost 40 years. She was shocked when I finally got her to shop around. She just couldn't believe that there is ZERO value in customer loyalty to insurance companies anymore. None. Zero. Zilch. Nada. At least that's their perception.
It pays to shop your policies every 3 to 5 years. USAA seems to be the sole exception, I've yet to hear anything bad about them.