Plus there are scenarios where choice is not available, for example, Comcast as the only ISP in town etc.

I suppose one could choose not to use the Internet in that case but that's not really a viable solution.

It's an asymmetric fight which individuals are on the losing end and given what we now know post-Snowden, I'd argue that greater privacy protection is absolutely necessary and available to all those who desire it.

this argument is irrelevant; as whether adults can give informed consent or not is not important (at least) here. e.g. adults have voting right, at least in some countries,including USA (whether they give informed vote or not is not even checked just assumed) but the children don't have this right. It is outright wrong and unethical on google's part to steal a kid's information especially after declaring they are not doing it.