Totally unrelated.Turn off animations. It's the first setting I toggle off when setting up a phone.
My wife’s XR isn’t lagging in any way (TBH even my son’s SE isn’t really lagging), so it must be something else.Yeah that's what I thought first but before doing anything I wanted to know if there was something to fix it besides a restore. I hate to restore my phone. Specially with my photos.
It's probably an app running amok in the background. Check battery and cellular data to see if any apps are using a surprising amount of either. We have an iPhone X and an iPhone XS in our family that are both running iOS 13 just fine. So is a 9.7 inch iPad Pro.