Sometimes these types of policies are not that much more expensive than having one joint policy. If you both pass away it would mean that your beneficiaries would have more of a payout.
A joint policy would end as soon as one of you die and if you had two separate policies and one of you are still alive it will continue until the end of the policy or on death.
It is important to note that everyone’s financial situation is different and it may be that these are is more suited to your circumstances and budget.