Exactly. We need a standardized method for meta tags that accommodates arbitrary user (or rather service operator) defined categories. We also need a broad push to force all websites to adopt said tags so that parental controls can work effectively. Government enforcement of particular categories is one option there (but not the only one, browsers could just start refusing to load any site that doesn't send the tag).
I think you'll find that trying to neatly bin the internet into neatly defined categories is something of a fool's errand. I guess the canonical example is centuries old fine art that shows a bit of nipple.
what about whitelists? this never comes up anymore. I can load profiles from the 'child safety council' if that's what I want, and should expect to cover some of the overhead in evaluating all the submitted links. particularly in an educational setting, part of the problem is kids playing games and hanging out on social instead of working.
it seems a lot more tractable than trying to classify everything and get everyone to play along. let 1000 different filters bloom.
what's fundamentally wrong with that approach?
Whitelists have the exact same problem you're objecting to. Not everyone will agree what should or shouldn't be on one.
In practice I don't think it's an issue. What I'm arguing for is the infra to facilitate self categorization and (likely) also a legal requirement limited to only a few specific categories. For example the government might mandate that porn, social media, and user generated content all be accurately tagged and provide legal definitions.
Nothing about what I describe would preclude additional layers of categorization such as (but not limited to) whitelists. In fact it should improve such efforts by providing a standardized method they can use for arbitrarily fine grained categorization that will be compatible with other software out of the box.
Note that my tagging proposition could be applied per network request. So if the service operator wants to it should facilitate filtering out (for example) a comment section without blocking access to the rest of the site.
the point being that instead of there being a kind of commission to create a schema, there are a whole bunch of different whitelists. so if your religion objects to the existence of mangoes, then you can subscribe to a mango-free internet filter.
and instead of burdening the isp the publisher of mango sorbet recipes with ticking off all the right schema boxes, this can all be enforced at the consumer.
all the rest of these approaches kind of assume that there is 'reasonable' and 'unreasonable' content, and that we all mostly agree on the difference. which I think is fundamentally fallacious. do you really think we can agree, as a species, what PG-13 should mean for the entire internet?