This is such a naive take, I see it a lot. Have you considered they can:
* Buy one themselves
* Get / use a friend's
* Use public internet access points
* Need one for school
* Use the smart fridge / tv / gaming console / anything with a browser
* Access stuff in Minecraft, Roblox, etc
You can only stop it by going offline and raising them in a cabin in the woods, which is a whole other thing.
What you can do is give them The Talk, of course (but that only helps / prevents to a point, it's more to prepare them for what they may find or how they can identify problematic things). And the other is to push back as a community effort, with e.g. many schools banning kids from having phones in the first place.
Have you considered that even if unwanted material was only accessible in physical form with age restriction for buying. Like porn magazines, cigarettes or alcoholic drinks, kids can still access them and find a way around it. You can ask older generations. Perhaps you can't stop it by "going offline and raising them in a cabin in the woods".
Best is to assume they have access to it one way or another if they seek it. The discussion should not be about banning vs allowing, it should be focused around how to deal with situations that arise regardless.
Education about the subject and why kids shouldn't seek access is quite effective, additionally they will be informed once they are allowed access. Think about how the last decades saw a sharp decline in smoking and alcohol consumption.
I think the earlier commenter is right. If a parent fails to... well... "parent" that's on them. Locking down the internet to republican-approved sites only is not the answer.
One problem (there are others) is that it's not always possible (or easy) to not give your kid a smartphone, or access to social media.
Imagine that your kid doesn't have those and is having a hard time at school because all the other kids do have them. They have a whole culture based around those, and your kid is excluded from it. What do you do? Tell your kid that it's okay to wait 10 more years before hoping to not be excluded?
* Buy one themselves
* Get / use a friend's
* Use public internet access points
* Need one for school
* Use the smart fridge / tv / gaming console / anything with a browser
* Access stuff in Minecraft, Roblox, etc
You can only stop it by going offline and raising them in a cabin in the woods, which is a whole other thing.
What you can do is give them The Talk, of course (but that only helps / prevents to a point, it's more to prepare them for what they may find or how they can identify problematic things). And the other is to push back as a community effort, with e.g. many schools banning kids from having phones in the first place.