Chatgbt is reporting literal fractions of 1%.
What was the actual question that you put to ChatGPT? Did you ask it for its sources to back up the results ?
I’ve just put the question to ChatGPT
For street walkers it declined giving a figure on the basis that there was insufficient information for it to work on.
For a general risk of unprotected sex it gave some figures for the risk of HIV, mostly as a fraction of a percent but higher for unprotected anal sex.
Bear in mind that ChatGPT is not a statistical analysis AI product, let alone an STI analysis product. It’s a text generator.
The model reads through your question / prompt, then seeks out a series of words that could follow in response, it doesn’t even seek out an actual answer - it picks the next word that is more likely to follow its previous word.
If can only give a probability of it has a paper etc in its training that has information on that probability.
Now to the matter of your question.
The chances of an STI from unprotected sex are increased due to the willingness to have unprotected sex - if they are willing with you then they are willing with everyone
Even protected sex is not risk free.
In general a sex worker may be of less risk of passing on an STI than a one night stand - they are most likely to use protection, to have regular tests, and to be aware of risks
A street walker is in a more vulnerable position in general, they are at risk of being the victim of an attack, and with just that are potentially / probably in a more desperate situation to take the risk. Drug use may bring them to the street and the street may bring them to drugs / more drugs. Needles carry added risk, even without shared / reused needles their use is likely to be less sanitary with even more riding infection (not just STIs)
The excitement of the many risks may be the reason why it is sought as a fantasy
It’s not worth it