That's a great question. Having a positive duty of care is a really critical component of the Canadian bill, because it says you have to be actively thinking about how your product might be misused and be designing proactively for it.
Parental controls can be really powerful. They are one set of tools, but not all children have parents who understand technology well enough. Remember, most parents today didn't grow up as a 10-year-old with a smart phone, or I hope not. It means that we need to make sure there is, at a minimum, a floor or a net that is catching all children.
We also need to ask whether we should be putting the obligation on parents, when they have so much to deal with already, to also stay abreast of exactly what threat is coming from where and what setting and toggle they need to put on their phones.