>porn
China and a lot of islamic and east-asian countries also banned porn and guess what, they're some of the biggest porn watchers in the world because VPNs are a thing and people are hooked for lack of better alternatives because their lives are not amazing and beating their meat to porn is one of the few cheap escapisms they have. If it's legal, at least it's a problem we can openly admit, talk and address through official education and care programs.
>Betting
Same as above, it's escapism for desperate people. People gamble more when the economy and their lives are FUBAR, even if it's banned. You're focusing on the effect instead of the cause. We already tried banning vices before with prohibition and it didn't stop shit, it just moved underground. What I think should happen is gambling should not be allowed to be advertised at all both online and offline, and should not be so easily accessible like on your phone or close to where people live. People get hooked because the first hit so so accessible and frictionless nowadays and ads are everywhere. That needs to stop. You wanna gamble, go to a dedicated regulated casino far out of town and you can only gamble limited amounts, not be able to connect your checking account to the pokie machine.
>onlyfans
That's the digital version of the world's oldest profession and it survived for thousands of years for a reason. Good luck banning it, I'm sure you can somehow end something that's been prevalent since the dawn of humanity.
I'm old enough to remember early internet social media sites of late 90s to early 00s, and women there were posting naked pics of themselves online FOR FREE, just to farm compliments and admiration from strange men online, and that was way before Instagram and onlyfans would allow you to monetize your looks. You won't fix the biological attention seeking female behavior and the male attraction to female looks, by banning onlyfans. I would suggest education, a strong father figure present in the family and therapy.
>should all be banned for a healthy society
Like I agree with you in principle, that those things are bad and ideally should not exist, but the thing is that all of the above are effects of a decaying morally and financially bankrupt society full of atomized people chasing money and attention to survive and get meaning, that lack opportunities, families, strong communities, strong support networks and a societal fabric tying them together(in the past it used to be religion). They indulge in vices because they have nothing better to live for. Banning those vices won't fix this, they'll just find new hedonistic way to ruin their lives. The true solution is addressing the cause, not the effect.