There’s always company self interest built into these things, at least for the ones that have actual system level access to be able to properly work.

An example being Google’s family link, which for the most part is pretty comprehensive, but you can’t turn OFF the Google search at the bottom of the page. No, it can be forced to ‘safe search’ but they absolutely MUST have the ability to use it because reasons.

Same with the play store, you can limit the ratings available, but they MUST be able to browse through it without limit to be perpetually distracted by the YouTube previews and all the previews, reviews, etc trying to hook them into some $1.99 a box game.