Crime A is $2500 fine or 2 mos in the slammer, let’s say.
The evidence that would convict me is worth a grand. I destroy it.
The penalty for destroying this evidence should not exceed the original crime or value of the property I destroyed in any rational way.
The rational reason is that this is a behaviour we want to discourage. We want to diacourage it because it makes it more complicated and more costly to catch criminals, and more likely for them to get away with their crimes.
There is the idea of commensurate punishment. 20 years for destroying evidence for something that while serious didn’t defraud anyone, maim anyone or cause damage I think is unreasonable and unconstitutional.