Apparently there is a cell phone which does not include internet access, social media, or app store.

https://gabbwireless.com/product/gabb-phone-plus

In theory, this means no porn, video games, or internet access to bad and/or time wasting material.

The phone does have a camera and permits texting (but links are blocked and there's no internet access by any means anyway).

The benefit is that you can still track your kids with GPS, and contact them when needed.

The phone does not use whitelisting, unfortunately (i.e., whitelisting means only preapproved numbers could call or text), but you can block unknown or unwanted phone numbers (although a kid could also unblock them).  So in theory, it seems that another person could text your child inappropriate material (e.g., a pic?).  But if your child isn't allowed to give their number out, then that isn't a risk (except by spambots randomly sending vulgar material to random phone numbers?  But they say spam filters are supposed to stop that).

And apparently, there is a log available to parents showing who and when a text or call was made/received, but it does not show the content (so the safest rule would be to keep the kids from being able to give their number out).

https://support.gabbwireless.com/hc/en-us/articles/9253652485399-Can-I-track-and-monitor-my-child-s-text-messages-Usage-logs

So in short, the only risks on this phone appear to be what could be texted to them by other kids (which could include pics, apparently, but nothing on the internet).

What do you think?

PS: I did notice a couple apps come standard that would be objectionable (a music app, and a "spirituality" app), and I do not know if these can be deleted or disabled.

Personally I would be most comfortable getting either a dumb phone. I suppose the phone mentioned may be comparable to other very basic internet-connected ones available, which offer only the most basic necessary apps and no true internet access. The smart watch phenomenon in any form is intrusive and unnecessary in my opinion.

If parents can monitor their children and control their activity, can the company? What about the State or (((Security Services)))?

I have a Lively (used to be called Jitterbug) phone, cheapest, original, ‘90s-‘00s technology, non-internet model that has voice, voice mail, old-style text, phone book, archive, a mag-lite.  Unlimited calls/texts costs me $12.50 per month.  The phone itself was $10.00 on sale with an AARP coupon.  It has large-print everything. 
It’s “chill factor” is exactly zero, but in a recent four day bout of intermittent power and internet outages, (due to underground cable cut), it worked perfectly fine when all the iPhones and smartphones were down.
P.S.  I am an adult who just doesn’t want the constant distraction of texts, calls, feeling that every beep, bell, vibration needs immediate response.  I also do not want to be overwhelmed with spam, advertising on email, and I don’t use social media.  It can take grainy photos, but the send option doesn’t work to anything via internet.
Sorry, Matthew, but no CathInfo on it, either.  I use internet at the times of my choice on my tablet without having to sacrifice the ability to summon help in an emergency or have a chat with a friend.  It gets pretty good reception, working in remote places where WiFi does not.