It protects potential future victims - both from SBF and from those who might want to emulate him.

Which is why I think the sentence is too low.

There are other ways he could make reparations. One would be to have one-to-one meetings with his victims, where they tell him in person how his actions affected them.

There's a fair chance it would bounce right off SBF, because he clearly has serious personality issues.

Then again, maybe not.