It should be your choice to wear one.
If your kid can't swim, it's your job to teach them or keep them safe. If you're not doing that, should it not be on you, that Childs parent, to deal with it?
Where does personal responsibility start, and social intervention begin? Autonomy, responsibility, individuality are the things that should be under discussion... Not save the children.
You might think that's harsh but add in privacy to the above list, and make the topic "searching all your pictures for CP" (as some laws are attempting to do) it suddenly becomes over-reach.