The point I try to get across is to separate "promiscuity is inherently bad" from "sex can have serious negative consequences that you should appropriately plan for depending on your risk tolerance."
Another way to think of it: it's also highly likely that if you go to a crowded event that there are tons of diseases you can expose yourself to. Pre-COVID, people used to talk about getting "SXSW flu", e.g. with so many crowded events at SXSW it was nearly impossible to avoid getting sick. Importantly, at some times (obviously when there was a high prevalence of COVID), I think this risk is too great and crowds should be avoided. At other times, though, I think it's utterly reasonable to think that the risk of a cold or flu is worth it to go to a bunch of fun concerts. Nobody ever talks about "You know, there will always be a ton of dangerous diseases associated with concert-going, so you should always avoid them."
So when it comes to sex, I find it totally reasonable to adjust your behavior based on the risk at the time. Currently, e.g. for a gay man on PrEP, lets look at potential risks:
1. HIV risk is extremely low for those who adhere to PrEP.
2. Most bacterial infections can be cured straightforwardly with antibiotics.
3. The biggest risks are then (a) lifetime viral diseases, primarily Herpes, and (b) at this point, multi-drug resistant gonorrhea.
Thus, I think it's important to be aware of #3 and to take precautions, again relevant to your risk level, accordingly. What I don't think makes sense is to say "But you never know what could spring up!" That's true, but if you look at the recent monkeypox outbreak, I think a lot of people had the right approach: when the outbreak was publicized, many people (a) stopped or reduced their number of sexual partners and then (b) got vaccinated as quickly as possible.
The primary point I'm making is to disentangle the real risks associated with sex (and to treat them dispassionately) from the the moralizing around "you're a dirty whore if you have sex a lot."