Yeah, insurance is best when it is over a large pool of people for something that is unlikely to happen but would be catastrophically expensive if it did. Because the insurance company makes a profit for the service of managing the pool of money.
Insurance is like gambling. The money is all coming from the customer, some of that money is going to the customers, and the house always wins in the long game.
There are many things worth insuring. I don't believe phones are one of them in general. The population-to-claim ratio is too low will generally make it less cost effective than just "find a used something that works on Swappa"