In general, retirees don’t need life insurance UNLESS their pension or Social Security is depended upon by the survivor. In general, if nobody else depends on your income then you don’t need life insurance. But, if someone as a survivor depends on your contribution of income then how do you replace that lost income?
One way is to have assets saved up that you are not currently using. The assets then spring into action to provide the income the survivor needs. If the assets are not there, then that is what life insurance does … the proceeds are invested and become the assets needed to provide the lost income.
Otherwise, the survivor may need to make an unplanned adjustment to where and how they live.
Therefore, Life Insurance replaces lost income for those who still depend on that income (working or retired).
Disability Insurance replaces lost income when you are still above the ground (and still working).