The term "victim" is vague, but central to the claim. What defines a victim in this scenario? Without a clear definition of what is victimization and where culpability ends, we can't come to a conclusion.
The punishment brought on to criminals for their actions are for either their correction or containment so as not to be disruptive or detrimental to the rest of society.
Both 'victim' and 'crime' are twin concepts. Like if you say 'top' you then imply there is a 'bottom'. If at least one specific person is not entered into a court record as a victim then proving a crime should not be possible since the word cannot make sense in the context.
Actions can have negative but not immediately obvious consequences for society as a whole. Gradual social change can have disastrous affects for those a few generations on, sometimes sudden, with the original criminals no longer around to be held accountable. Many laws are a result of age old wisdom
People have a duty to society. Suicide has no immediate victims other than the person who willingly committed it, but even ignoring the emotional impact on people around them, they might have children or family who depend on them, and it erodes the stability of a society.
As long as we have state sponsored support for non-producing individuals, there are no victimless crimes.
e.g. personal drug use, while seeming 'victimless', may result in reduced productivity, total welfare dependence, treatment, or death at worst. This causes harm to society.