Group life insurance from employers is a wonderful benefit, but there are several reasons why you should not solely rely on it for coverage. In most cases, group life insurance simply doesn't offer enough protection for your loved ones. It might match your salary for a short period of time - possibly one or two years - but in the realistic scheme of things, that is not enough to prevent financial strain. What happens when it runs out? Will your family need to sell your home or liquidate retirement assets?
Another reality is that you will typically lose the coverage of your group life insurance policy if you leave your job. And if you've developed a medical problem, you might find it difficult, or impossible, to get new coverage. Some employers allow you to keep your group life insurance policy when you leave, but it usually costs significantly more than when you were employed with them, and there is always the possibility that they will stop the coverage or switch to a plan that won't accept you.
Because group life insurance plans through employers typically don't offer enough coverage and might not be available to you if you leave the company, it's a good idea to consider yours a supplement to your life insurance - a welcomed bonus, but not your main policy.