So, do you want them to ban all child video ?
And keep parents from uploading them too:
https://www.theatlantic.com/technology/archive/2019/02/when-...
Can a minor legally grant copyright to another entity by accepting TOS?
As an example of why, this much-criticized article where a mommy blogger's fourth grader discovered she'd been the subject of a bunch of columns: https://www.washingtonpost.com/lifestyle/2019/01/03/my-daugh...
Maybe an ideal service would offer both— paid private and shareable containerized hosting and an open-source or free-download host-your-own option.