Why don't we listen to sex workers themselves, when they tell us what policy changes they want? If sex workers say sex work should be criminalized, that would hold some weight for me. If they're exploited, I'd like to hear what they think would actually help them.

E.g. when Norway criminalized buying sex, the prostitutes own organizations were against it and argued it'd push a lot of the sex trade underground and make the women less safe. They were totally ignored, and they continue to be ignored when they repeatedly warn that they're unable to report violence and crimes safely, in part because it makes police aware that they're prostitutes, and by extension that there will be people visiting them that are likely to break the law, and that their landlords are potentially breaking the law (if they're aware of the prostitution; which they will be soon enough if the police takes an interest).

If they were listening and disagreeing, that would be one thing, but there's a staggering amount of moralising from politicians that do not even try to talk to the people they claim they want to protect. And that makes me think that their motives are more to do with getting activities they don't like out of sight than about helping the people involved to get out of it.

But this isn't the same thing. You're talking about human trafficking, not sex work as a whole.

If Nike trafficked a bunch of kids to set up a sweat shop in North America, we'd be upset not because shoes were being made on our continent, but because of the trafficking and exploitation of underage workers.

Analogously, if some scumbag trafficked a bunch of women to work as prostitutes, we should be upset because of the trafficking and the coercion and strong-arming you describe, not because of the sex they engaged in.

So voluntary sex work should be perfectly fine, but it's not, and most discussions surrounding sex work seem to classify it as inherently exploitative, which simply boggles my mind.

I don't see how this is any different than taking any other menial, low paying job because you have to make ends meet. No one really wants to clean public toilets or work at Wendy's.