That says it all. Many, but not all. Many people are killed for their organs, yet organ transplants are legal. People are kidnapped and sold for work in Asian factories, yet working in factories is legal. Of course people use and will continue to use sick methods of getting girls who don't want to do certain things to do those things. That's not going to evaporate. The question is whether making it legal for girls to willingly do it will help. The answer is probably a yes.
I'm not absolutely sure I would support it, but I don't think you've given me any reason not to. All these statistics and the degradation of societal values are irrelevant, really. Do we really need to go through all the dangerous jobs in the world? Because very close to 100% of the most dangerous jobs in the world are legal. Danger is not a reason to make it illegal, as long as the people do it do it willingly and do not harm others.
But underage prostitution would still be illegal even if prostitution were legalized - and you've shown nothing to even imply legalization would make this increase. If anything, government oversight would tend to decrease this kind of child abuse.
If anything, your examples have shown that legalizing prostitution would be a benefit. Nothing you've cited here would be worse than it is now and many things would get better with legalization.
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