As many others have mentioned, I could go without, but it would make certain things more difficult, and I'd end up carrying more things. It's also one (two with the watch) thing for me to charge at night instead of 3-4 things.
The thing for me is "intentional use" vs "unintentional use". ScreenTime isn't perfect, but it's a start, and at least gives me an idea of how much I'm using my phone. Being present for life is important to me, and often I'd rather view life through my own eyes than through the phone screen (missing out on a photo opportunity in order to pay more attention to what's actually happening).
The thing for me is "intentional use" vs "unintentional use". ScreenTime isn't perfect, but it's a start, and at least gives me an idea of how much I'm using my phone. Being present for life is important to me, and often I'd rather view life through my own eyes than through the phone screen (missing out on a photo opportunity in order to pay more attention to what's actually happening).