I dont make blanket arguments like getting rid of all safety regulations because there is one I think is pointless and overbearing.
That said it is a voluntary action by both actors who understand the risks. If we are going to play this out logically. Why should actors be granted these protections by the state and not the rest of society? The porn industry has tight self imposed regulations about STD testing. Far higher than anything we see in the wild.
But the only argument you give for being against it is easily applied to any safety standard.
And once again in your post you use 'voluntary action'. The fact that it's voluntary, or that people know the risks, is IRRELEVANT when it comes to workplace safety. That's what people are trying to show you. It doesn't hold water because it's easily testable against other safety standards which I imagine you agree with.
The only people who can legally be paid to have sex are porn actors. If prostitution was legalized I'm sure that they would require the use of protection as well.
Now if your argument is that the current testing is enough to ensure the safety of actors, then say that. Don't try to imply this is some kind of authoritarian issue about not allowing individuals to have consensual sex. Any of the actors mentioned are allowed to have unprotected sex with each other, and allowed to do it on camera. They're just not allowed to be paid to do it.