They're an adult product not suitable for children.

We've had a no phones / tablets policy for all of ours going on ten years now. I definitely notice the difference in phone vs no phone children.

The negative effects are becoming more widely understood by parents which is good. More children being smartphone free makes it easier for others to do the same. Around 30% is the key number.

We have this movement in the UK that is gaining traction. https://smartphonefreechildhood.co.uk/