Maybe it's a bet on LLMs/Siri AI as well: all of the not-iPhone devices become more useful if you can control them well with your voice.
I think people do feel some tension about staring at their phones all day and like the idea that the phone can stay in the pocket or on a desk while stuff like the Watch and maybe a HomeView or a HomePod could cover a lot of the little usages along the way. (I'm not sure people would ACTUALLY use them that way, but I could see it driving some sales.)