You may automatically assume that buying a joint life insurance may be cheaper and better than buying two single life policies, BUT this is not necessarily the case.
For starters, generally taking out two separate life policies may be marginally more expensive, but you will get twice the pay-out if you both die during the insured term. With a joint single life policy there would only be a single pay-out.
Also, if you take out a joint life first death policy (often used for covering mortgages), the policy would pay-out then cease in the event of either of you dying during the term. This will leave the surviving partner having to take out a new life policy, which is often a lot harder and more expensive give the increased age of the surviving partner.
Finally, having each life separately underwritten and insured on its own merits, makes each party independent of the other. Hence the policy is not dependent on the survival of the marriage or partnership. With individual policies, all the potential arguments (like changing ownership or cancelling a joint policy) disappear.
So don’t just assume a first death joint policy is best for you.