The 4GB of RAM in the new iPhones is completely wasted. I have an iPhone 11 with 13.3.1 that was installed as a new phone (no backups). Any non-Apple app is being unloaded from memory after sitting in the background for some period of time (even if there is free RAM). So any progress, edits you’ve made is lost. The best way to test this is when you wake up in the morning, all your non Apple apps will reload (often with their splash screen logo). Native apple apps like messages, calendar, notes etc will be kept in memory and save their last state. Seems like iOS 13 is made for 1GB ram devices, all that extra 3GB must be going into processing photos for the new camera. /s