Drowning is the leading cause of death in national parks and recreation areas. It's scary how powerful water is.
I’ve lost friends to drowning in calm looking waters where they got trapped in hidden potholes in river bed.
Water bodies are no joke.
Looks entirely harmless but is incredibly dangerous in some parts. Apparently the river "turns on it's side" creating a narrow but very deep stream with very fast underwater currents.
It's powerful because there's a lot of it.
Also it's deceptive as hell. See all the stories here about strange pockets of rivers that almost killed people, or the author's own note about the 252 degree hot pockets in Yellowstone Lake with an average survival time of 20 minutes.
I think when people see water they're tempted to think it's a nice pool or a lazy river to enjoy - when really it's most likely a death trap.
Frequency/exposure matters. A lot of people swim. Not a lot of people choose the more extreme hike that's borderline on rock climbing.
The danger of the typical or average swim is basically nil. Worrying about it other than just knowing there's baseline danger (that you can amplify by poor decisions if you choose to, but same goes for everything in life).
It's not a lie, because the results are the results. And spreading awareness of the outcomes is about reducing the exposure that you mentioned, especially amongst the unprepared/unskilled.