What issues do sippy cups cause?

I just want to say that my kid did NOT get the 360 cup until about 13 months. We started about 9 months but she couldnt get liquid from it and didnt understand maybe sipping. When served a bottle she used Avent nipples so I first switched to the Avent sippy cup spout (not much of an improvement over bottled but a step).

We focused on open cup and used the Beaba one at meals bc its heavier on the bottom so it doesnt tip as easily. I also let her practice with an open cup in the bath -- i would fill with cool water from spout.

Then after a break of about a month i gave her a 360 cup and like magic she used it fine.

They can have water from sippy cups (or nipples/bottles), just no caloric drinks because it is associated with cavities.

Mine was a low effort booby baby and we got her drinking from a straw by quirting juice into her mouth from juice boxes.

Dentist said those circular no spill cups are fine.