You could just get any phone, and then delete the APN so the phone won't even be able to access mobile data if the SIM offers it.
Yep thats the problem, anything that has a camera will connect to internet.You're not going to find a 'dumb' phone with a decent camera unfortunately
This is basically what the new Nokia 3310 is for.
Teaching kids a lesson of what it was like.
The built-in Opera Mini browser can handle Twitter and Facebook at a push.
https://www.engadget.com/2017/02/26/nokia-3310-return/
You're not going to find a 'dumb' phone with a decent camera unfortunately