At that age I was riding my bike the 3 or so miles to the nearest library to check out books.
In the far off long ago world of the 1990s, when crime was stupidly higher than it is now.
That's about 0.8km ~ 1.2km. That's literally 10 minutes of walking, probably less as an energetic kid. What do you imagine will happen to your kid if they're left alone on a 10 minute walk?
It's about as cliched as it gets as a response, but at that age my friends and I were gone for hours on end much further than 1.2km from our homes with 0 devices of any kind, other than 1 or 2 kids that were lucky enough to have a Nokia.
I'm not saying you are wrong or right for wanting this, but it brings 2 thoughts to mind.
One is a reminder that our parents and beyond always joke about, back in the day throwing a few blankets in a car and driving 12 hours north for the weekend and having no way to contact anyone and "they were fine".
Second is this feeling of overlap between having a child grow up with a phone constantly on them, and our mental attachment to having them. Everyone is aware of this emptiness / stress that occurs with many people when you leave the house without your phone these days. You feel this strong mental attachment / reliance on this connection to the world. Now, are we forcing children to have that same mental reliance on these devices by starting them so young?
Again, not saying you are right/wrong to want it, just something that came to mind.
What're you actually concerned about? Is that going to helped by your child having a phone themselves (vs some bystander)?
Then do what I did with my child as a half-way compromise: turn the phone off when at home, never let it into their bedroom, lock down the majority of functions (parental features) to the basics needed during the day and check usage.
There is no reason why parenting and ground rules can't come into play. It's not all-or-nothing.
Based on the comments here, most don't seem to understand that. Restricting access requires someone to actually parent and that seems to be too big of an ask for most of these folks. Instead a blanket ban is the only solution. And then it's only a solution if you can ban everyone else's kids from having phones as well so their precious little snowflake doesn't suffer from FOMO. There is a post on here about a dad whose relationships with his children were "ruined" by giving them smart phones. As if he has no agency outside of giving them the phones in the first place. It's ridiculous.
1: Pofung BF-T15. Two pack was $17 on Amazon at the time. Baofeng is an adjacent brand.
What element of safety does the phone confer?