Yet humans have fared mostly fine as a whole with even a moderate level of those things, legal or not, consistently happening throughout history and cultures. The biggest problem we have is when these vices are driven underground so the vice itself is conflated with the additional risk of having to put one’s self in a dangerous situation to engage with it.

Looking at western culture (the only one I feel confident speaking about), we are still bound by puritanical values that were imposed as control mechanisms but managed to sneak their way into a set of cultural norms as a moral code despite their actual value to us not being evaluated and actively selected.

> Looking at western culture

It's not a "western culture" thing. Many western cultures do, sure. Many eastern cultures do as well. Not literally puritanism and that specific history, but very similar kinds of thoughts and ideas.

It's absolutely not western nor is it puritanical. The value is clear, there is a wide funnel like no other from starting drugs to ending up on the street, etc. Other societies, asian, middle eastern, etc found their way to the exact same values, sometimes enforced much harsher by the state.

This libertarian stance where neither you nor the state should care about how your neighbors lead their lives is the exception, not the norm, and it has its merits, but the cost of this ideology is obvious.

There’s still value in curbing many of these vices. Smoking is a good example. You can smoke, but you can’t advertise cigarettes, you need to be an adult to buy them, you can’t smoke them indoors, and we’ve all been subjected to propaganda from birth about how smoking is bad for you. If you have all of that in place (which took decades for tobacco and now people are trying to ban it in some places), you can have legal vices.

A better justification is, "prove that it's actually harmful using sources other than your gut", and "suggest a method for controlling it that doesn't almost immediately devolve into puritan witch-hunting, racism, and/or misogyny."

Obscenity?

Do you think 2 girls 1 cup, blue waffle, or ‘the jar’ helped anyone in society to see?

If so, how?

Should they be required watching in elementary school? If not, why not?

Supposing the premise that these things were entirely unhelpful to society, I would argue that the obscenity specifically is not what makes these things unhelpful.

Then what was?

Not OP, but it is possible for something to be both "obscene" and "helpful" (maybe we should say "of value"?) Say... footage of Hiroshima? Or the liberation of concentration camps? I'd say those are examples of things that are both obscene and have value.

So I think you're looking for another property those videos have in common. It might be closely related to obscenity, but I think it must be a bit more nuanced than that. Why are those videos valueless? (I don't know the answer).

Depends on how you define helpful or how much of a requirement for content to actually be “helpful”.

A strict definition might require content to have academic or intellectual value (implied by the remark about it being shown in an academic context) but this would also exclude a vast majority of non “obscene” content. Further, if you could swap the obscene elements for non obscene elements, I would argue the “value” of the content, as measured by its helpfulness, stays the same.

This all moot, however, as it’s likely not the right conversation to have. There is more useful discussion to be had on harm caused as a result rather than any sort of value judgement.

> Vices like gambling, obscenity, prostitution, drugs, etc are banned or heavily controlled societies over because they have significant negative cultural effects

Do they? Citation needed. So far it seems that marijuana consumption leads to far less violence than alcohol, and proliferation of porn leads to much lower rates of sexual violence.

> if everyone in your community is addicted to vices, that DOES affect me

Then choose and manage your own community, but don't push this view on the whole country. Dozens of millions of people (I don't know what country do you live in, so not sure about the population) are not a "community" that you can put under the same norms. If you think that porn is bad, it's your right to do so, and to find likeminded people to build a community that shares these values. But why would you want to force it on other people?