Not that many people dream of becoming prostitutes. People don't have a favorable attitude of the worlds oldest profession. Many countries ban the act while others allow it in specific locations or only under certain circumstance.
Is prostitution normal in evolution?
Is prostitution the personal freedom of two consenting adult humans?
Evolution does allow acts of procreation between consenting adults like in prostitution. The effects of the act are the outcome of evolution such as reducing the human population if condoms are used, creating disease resistant humans through the process of trail and error, or uniting sexually active genes.
There are even genocide laws that make it illegal to separate procreating humans.
Article II: In the present Convention, genocide means any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such:
(d) Imposing measures intended to prevent births within the group;
Hitler separated Jew's by gender to prevent them from procreating so logically anti-prostitution laws are an extension of Nazi ideology.
If a prostitute is paid money for a small item such as a trinket and the client gets a receipt for the sale, but at a later moment the couple has sex, the act is not prostitution. There is a separation of sex and money, but some people will not agree that it's not prostitution.
The bad effect of prostitution is spreading incurable diseases, but overcoming the transmission of illness would leave certain types of prostitution free of argument.
Requiring health cards before sex for one day after getting a medical exam for both the prostitute and the client and also using a condom would eliminate diseases regardless of the expense. A brothel and a medical clinic combined.
In reality, arguments opposed to prostitution are the personal opinion of individuals, unrelated to the personal freedom of prostitutes and their clients.
In the end, dating and sexual intercourse are always available and are not that different from prostitution except for the union of slightly different gene types such as sexually active genes not dependent on resources like money.