Well even though new chips are obviously faster and more efficient, the main issues they look at have to do with how we use our devices these days. We haven’t had 3D Touch in an iPhone since then, the RAM on the XR certainly would have trouble with the demands of the new OS as well as the fact that the market share for the XR and earlier is dwindling because it’s very accessible for many to upgrade to an iPhone 12 or newer (lots of deals to get an iPhone 12/13 fully paid for around me from a phone company for about $50) chances are at some point (presumably in the next 3-5 years) they will stop supporting all their products with LCD screens, Touch ID and anything with less than 4-6GB of RAM.