Child porn involves children

Production of the vast majority of such drawings involves literally zero real people let alone children besides the artist.

Rape porn involves consenting adults pretending that one is not consenting. Real rape is bad, making rape porn is not.

Yet the abuse that many porn actress go through and didn't sign up for is incredibly high. But sure. Drawing small characters is worse than actual abuse just because they're adults.

There is an argument that says loli porn is victimless and helps pedophiles that do not want to offend to handle their urges. If the science shows that to be true (which would be difficult) then that would be a good argument. But as of now, I am not aware of any scientific consensus that says so.

Neither is there any consensus that says otherwise. You are basically using the same argument like "violent video games makes people want to carry out violent acts in real life"