Neither the original strain or delta variant are statistically a threat to kids. More kids as a percentage of the population are getting the delta variant because they can't be vaccinated. But hospitalization rates amongst them are actually lower than the original strain (hospitalizations/infections).
The flu and pneumonia are still statistically a much bigger threat to children than Covid.
https://twitter.com/ShamezLadhani/status/1424748595408998401/photo/1