On the other hand, a government that makes victimless actions into major crimes also destroys social cohesion as it means the law is clearly detached from what is just.

By all means, fast track the death penalty for child rapists. Even make a constitutional amendment allowing cruel and unusual punishments for that single crime. Treat paying for actual abuse images as a worse crime than commissioning a murder. Sky's the limit for actual abusers. But (legally) punishing the creation of fake imagery is absurd, and in practice punishing possession seems to be unhealthy for a free society.

Yeah obviously there needs to be a balance. But I think it's popular right now to be unbalanced towards allowing any and all victimless crimes not thinking about the effects they do have on society overall and in the long term vs any particular specific person immediately

Something can be legal while not being socially acceptable, and we can still strictly police related harms. Like with drugs, we can legalize them while still making e.g. smelling up an area with marijuana carry a public nuisance fine, or make littering with needles a misdemeanor (or more severe if someone gets injured).

If someone's only crime is being disturbing, the government doesn't need to get involved, but we can still not want to be around them and especially keep kids away from them.

I think that's a better balance than what we currently do.

Not saying I agree with legally permitting this kind of thing, but just addressing your comment:

If the government can throw you in prison for something, it better be for a good reason. If it's simply doing something "that doesn't harm anyone but is perceived as not conducive to social cohesion", that doesn't seem like a good reason. Many conservatives would say gay marriage, polyamory, tattoos, porn, foul language, and blasphemy are not socially cohesive. Insulting people or using slurs is not socially cohesive. Some countries imprison people for many of these things, but I'm glad the US doesn't.

I agree with you, but I would rephrase it as "people should have the freedom to do certain harmful things without going to jail for it".

For example, insulting someone, or self harming. Even things that "don't harm anyone" actually do, it's just the scale is too small to be measurable at the individual level. For example, substance abuse. If one people does it, it's hard to measure the harm to society. But if 300M people do it, it's easy.

Many people's instinct was to go here, which is maybe why our current society tips over into permissiveness. But a good balance can be reached without becoming brutal totalitarians.

One example is alcohol, a lot a lot of countries struggle with controlling it. Technically it's a victimless crime. It's easy for people to see how it affects society though. In some places banning it will be impossible due to local preference, but governments have creative ways to reduce usage. It's not totalitarian to run a campaign to try to reduce people's alcohol consumption, or to add taxes onto it which are shown to reduce consumption and related incidents.

It also doesn't apply to most laws. The law doesn't always require a victim or harm. Just look at speeding tickets or DUIs. You don't have to harm someone to wind up in jail

Both of those have clear harms, namely increased risks of traffic collisions.

That's not true. Increased risk is not harm, it's just a higher potential for harm.

You don't want to use that argument, because that's the same argument that has been and will be used for a lot of things, like gay relationships, transsexualism, any and all drugs, violence in media, etc.

But just because it can be taken too far, doesn't mean the argument is bad. Likewise, the argument for a social safety net is good, taken too far you get Communism. Does it mean we throw the baby out with the bathwater?