Genuinely, how do you expect someone concerned about child sex trafficking to receive this? "Oh, good point, I guess we can't do anything more to protect children because it isn't 'cost-effective'." Do you think that will be a common response?
>And then disingenuous opportunists keep proposing the thing that should never be done because they know it lets them paint you as the bad guy for having to tell them no again and again.
I'm not even disagreeing with this point, I'm simply saying your response can't just be "no, they are the bad guy". That is not a winning political message. That's why the democratic socialist faction of the Democratic Party in the US is growing in popularity. You can't just call your opponent bad especially when your opponent is promising to address people's concerns, you need to actually engage with people about their concerns and offer solutions.