> What casual runner goes running without their phone?

Judging by the answers you got, ones who have oversized phones and think that shaving a little weight is worth not being able to call emergencies (who cares, they can use a strangers phone if that happens, just like the guys who cycle and skip tools, patches and pumps and then end up asking people passing them by, and anyway emergencies happen to other people).

OTOH, I don't know why anyone would ever wear a watch after 1993.