Let's say someone steal a billion dollars through fraud and hide it. What should be done? Should they just walk free?
There's a difference between non-violent crimes (white collar crimes usually) and victimless crimes (possessing a small amount of controlled substances).
First of all, that's not a deterrent, though. If I can steal your money and all I have to do is return it if you catch me, I'll keep doing it. So you need some sort of punishment on top.
Which brings us to the second point... At minimum you should be fined, at least to cover interest gained while you held the money, probably more to cover emotional distress and otherwise.
Plus, at those kinds of sums, we're somewhere into "stole pension money territory" where we're only a few minutes away from "old lady took her own life after losing life savings".
I also expected the money is hidden away, such that the the legal system cannot get it back. Money can be laundered away. These are smarter criminals, not ones that just robbed a bank for cash and have it under their beds.
There's a difference between non-violent crimes (white collar crimes usually) and victimless crimes (possessing a small amount of controlled substances).