In other words he's not being punished for what he did; he's being punished to dissuade others from copying him. I think people should be punished for their actions and not to increase utility of society.
FWIW, I've read that multiple people committed suicide in despair of the financial ruin caused by SBF's fraud. So he did do things worthy of hefty punishment.
Stealing money may not inherently "feel" like a real crime, because money (especially digital crypto money) is a very intangible hypothetical thing. It does not resonate with our lizard brains like violence does.
However, it is a real crime. And harsh punishments like prison time are needed to remind us of that.
