As a parent, I welcome these changes. When people say, "parent your kids," this is what I need to do that: an os-level setting that serves as a source of truth, a browser that reads it, and sites that require it.

If you don't like those things then use another distro or create your own, branch a browser, and create your own Internet. I welcome that. Until then, don't say the contradictory phrases of "parent your kids," and resist any of the infrastructure to actually accomplish that.

This is silly. No parent who is seriously looking for your requirements is going to count on a UNIX OS setting to enforce restrictions on what their child can do.