Why term is so much cheaper
Term insurance only pays out if you die during the term, and most people outlive a 20- or 30-year term, so insurers can price it low. Whole life is built to pay out eventually plus fund a cash-value account and commissions, so premiums can be 5–15× higher for the same death benefit. For a young family, that difference is the gap between being adequately covered and being underinsured.
'Buy term and invest the difference'
The cash value inside whole life typically grows at modest rates after fees — often well below what a low-cost index fund has returned over long periods. So the common advice is: buy a large term policy for cheap, and invest the premium difference yourself in tax-advantaged accounts. Over 20–30 years, the invested difference usually beats the policy's cash value, and you keep full control and liquidity.
When whole life genuinely makes sense
Permanent insurance has real uses: covering estate taxes so heirs don't force-sell assets, providing for a dependent who will need support for life (e.g. a disabled child), business succession funding, or a high earner who has already maxed every other tax-advantaged account and wants additional tax-deferred growth. These are the exceptions — not the default a salesperson may present it as.