When it comes to renters insurance, the agreement is set between the policyholder and the insurer. No additional benefits will be given to your roommate simply by virtue of their being your roommate. And if you fail to make a payment, your insurer is going to be making those reminder calls to you, not your roommate.
That is not to say that you can't have your roommate covered on your renters insurance policy. If you like, you can have your roommate photograph their belongings and provide receipts. Then, you can add your roommate to your plan. Likewise, you can make an informal arrangement with your roommate to have them pay for a portion of the insurance payments, in accordance to the share of risk.
Right away, you can see how this might be making things too complicated: Roommate situations are, almost by their very nature, temporary. Someone may sign on to live with you for only a few months at a time before moving on to rent a place of their own. Or, they may move in with a new boyfriend or girlfriend. When this happens, you don't want to be left holding the bill for a former roommate's insurance.
There is the matter of liability. If someone is injured in your apartment, liability will generally fall on the landlord more than it will on you. But you can't always be sure who is going to be targeted in a lawsuit.
Keep in mind that there haven't been nearly as many cases of tenants being sued or held liable as cases targeting landlords. And there have been even fewer cases where multiple tenants added confusion to the proceedings. So, there is relatively little precedent to go on here.
For all these reasons, the best option is usually to have each renter bring their own renters insurance — if they are interested in being protected by such a policy.
Also Read: Preventing Fire Risks in Rental Homes