Note that I agree with your point overall. My kids have phones for times when they are away and might need to contact me. I'm just saying it isn't as bad as it sounds.
This isn't very compatible with also teaching children that they can't trust the majority of adults, and that every stranger is a potential danger.
I remember about 10 or 12 years ago, I'd answer every incoming call. Many were wrong numbers (guy who had the phone number before we was, I kid you not, some sort of wine salesman... people were wanting to order crates of wine). But I'd answer. Now, not so much. I get 15 calls a day some days, all are robots. I screen through voicemail transcription most of the time, unless I recognize the number. Blocking does not good. Numbers in my area code mean nothing... a surprising number of robot calls match my own exchange number (why? what's the point?). For 3 weeks a few months ago, one even matched my own phone number but for the last two digits being transposed, but it wouldn't leave a voicemail.
I no longer have the reasonable ability to answer strange phone numbers. If it were just mean, I'd chalk it up to some idiosyncratic neurosis and be quiet, but my own impression is that everyone else is doing the same thing. We not only tore down the old POTS network, we got rid of all the norms around it.
I also have a phone number from a different area and I blocked that area code and everything near it.
I have phone numbers in an area code that just seems to get flooded with spam calls. Even our unpublished numbers get them so it doesn't seem like directed attacks, just broadcast spam.
The robocallers have found that if the fake caller id given matches the area code and exchange of the number being called, that more of the recipients are willing to answer.
And from a robocaller's perspective, getting folks to answer is critical to being able to transfer them to someone in the scam boiler room for reaping.
that's not even true for adults. Why would you assume it's true for kids?
People can be wildly reluctant to just hand over a thousand or two dollars worth of equipment to a teenager in a busy street and hope they don't run off with it. Smartphone theft is still a thing.
I take your point though, but I have to wonder who in their right mind would go to times square to ask to borrow a phone. Surely you'd go somewhere less busy.
Who owns a $2,000 phone which isn't insured and should they really be leaving their house?
How about this, I'll pick a random day in your future while you're out doing stuff to show up and break your phone in half. How much is that going to ruin your day?