Not a great comparison, because unlike withh violent games or movies, you can’t say that there is no danger to anyone in allowing these images to be created or distributed. If they are indistinguishable from the real thing, it then becomes impossible to identify actual human victims.
There’s also a strong argument that the availability of imagery like this only encourages behavioral escalation in people who suffer from the affliction of being a sick fucking pervert pedophile. It’s not methadone for them, as some would argue. It’s just fueling their addiction, not replacing it.