It doesn't even need to be a permanent disability to collect. Husband broke a leg some years ago, and collected a partial benefit from his disability policy till he was back to full speed. That can make a pretty significant difference if hired help has to be brought in to do chores, etc while you heal.

At your age, with 3 kids, I'd be afraid to not have it. Think through your typical day/week/month/year with you being unable to do anything but sit inside and look out at what needs to be done. Coverage won't kick in until a certain amount of days of disability, so you're still responsible for that period of time, but after that, it's a pretty significant way to protect your family.