I think the main purpose is probably to provide a more-usable "dumbphone" experience. I know a lot of people (myself included) who would love to doomscroll less, but need a more full-fat version of Android for work or family. Using Digital Wellbeing and the like gets part of the way there, but not the whole way. With this, the weird aspect ratio means that pretty much all video is going to be letterboxed to a crazy extent, which could be enough to make bypassing those controls feel pointless. And then they used that extra space for a physical keyboard, which is genius. If this thing had a better camera, I'd be all in.