As a developer I hope the SE goes the way of the dodo bird. It's just about impossible to create an iPhone app that takes advantage of the screen size on the X and Plus phones, while at the same time making the app usable on an SE screen. There are some exceptions (notably games where things can just be smaller without affecting usability), but for the most part it's a mess dealing with the different form factors since Apple only provides for a single size class for all phones.
The death knell of the SE will likely be when the current 6/7 form factor moves to an edge-to-edge display.