Trust me, I had this in mind when talking about “different factors”. There are factors that reduce actual crime rates and factors that reduce the number, without changing anything in the real world.
It scares me that these stories don’t surprise me anymore. The same situation was within the UK, with them (of course) banning lolicon artworks, and prosecuting people for possessing them, but then keeping a list of individuals who happened to create grooming gangs targetting teenage girls and kids, from fear of racial tensions escalating. If I recall correctly, one of the politicians had the opinion of “If those (underage) girls come back to them, that must mean they like it”. They didn’t display any will to do anything about the situation, and I don’t know if anything was handled in the end.
The mere fact of absence of any shreds of evidence that such arts or sex dolls could reduce or increase sex crimes, making both possibilities equal in probability, and politicians skewing into one side over the other on false premises suggests to me that their attitude to protecting children is nothing than just performative.