while it's true you'll never truly eliminate the practice, legalizing it essentially gives social consent to letting others violate your body for money. do you really want that in your society? a cohort of people who produce nothing, who add dubious value to the economy, engaging in a personally degrading business, not to mention the additional mass disease vector that represents since sexual contact is such a great way to spread a wide number of illnesses. you're also signaling that it's valid for sexual desire to trump personal attachment. this type of hedonism undermines social ties and results in a weaker citizenry. and to the laissez-faire argument of "let whoever wants to do it, do it" - have you read about what's happening with the volunteer suicide thing in Canada right now? people with incurable diseases, or even diseases that are curable but expensive to treat, are being encouraged to just fucking kill themselves to curtail the burden on the medical system and to save their families money. many people are already forced into sex work for economic reasons - rest assured that legalization will make that situation much more dire. education, self-improvement, job searching, etc. are all difficult to accomplish. however, if you're reasonably attractive and have a vagina, it's not exactly difficult to find a guy who might be open to a little financial coercion for sex. how many people who could actually contribute positively to society will end up defaulting to sex work because it's easier?
imagine combining this with our current "gig economy" paradigm... download a convenient app to find pussy for rent in your area. corporate pimping, a whole industry of companies built on facilitating access to sex and taking a cut from it. young women being encouraged to fuck a little on the side to help pay the bills or put themselves through college. imagine dating in your 30s or even late 20s, where every available girl has almost certainly had their hole blown out by countless other dicks, far worse than it already is today. being in a devoted relationship is an economic disadvantage, unless you manage to convince your SO to allow themselves to be cucked to ratchet down the financial stress a bit. imagine your family being hit with a sudden debt you have to pay off ASAP - renting out your body is a good way to make some quick money. we can handle it, it's not like we're cheating on each other or anything - these are strangers we don't have any feelings for, and anyway, what's worse: doing a bit of side fucking, or losing the house? think of the kids.
nah, man, you don't want to open that can of worms.