Talking with my insurance agent:
If you have $50,000 in coverage and you get sued for a $1,000,000 due to an accident, the insurance company won’t get involved; they’ll pay the $50k if you lose and the other $950,000 is your problem.
If you have an umbrella policy (typically $1,500,000 in coverage) the insurance company is going to put a team of lawyers on your side. I believe adding the umbrella was ~$15 more per month…that’s a bargain.