Whole-of-life assurance and term insurance provide different roles for your protection needs.
Term insurance will be cheaper and is best used to provide money for circumstances that have a time period. Examples include repaying a mortgage or supporting your children until they are financially independent. Once the time has passed, there's no need for the protection. The policy will end and so will your premiums.
Whole-of-life assurance is better for providing money under circumstances that won't change. For example paying for a funeral, unpaid bills, providing an inheritance or inheritance tax on a large estate.