You can still buy a super basic Nokia phone that pretty much only does that, and it lasts like a month of battery - I own one, it's great to carry around in places where you might not want to risk your super expensive smartphone.
I'd happily give this to my own child so they can reach me in emergencies, but there is no risk of them going on TikTok or anything else. It's "just" a phone.
I don't know. And maybe you're right - but I'd bet it's the attempt by the school the quell all kinds of complaints from parents like "what if my kid gets suddenly lost on the way home? what then????" by giving them a phone that has some mapping capability, it's just crap - but I guess it will do in an emergency.
https://www.amazon.co.uk/Nokia-1-77-Inch-Feature-Phone-Singl...
I'd happily give this to my own child so they can reach me in emergencies, but there is no risk of them going on TikTok or anything else. It's "just" a phone.