> You made a mistake, there were consequences - but once that's over, you ought to be good as new.
The consequences for being found guilty of a crime are more nuanced than this suggests, although not so much in the US which is very focused on vengeance.
Let's take an example a sentencing example I sat in on:
The man had forged paperwork purportedly showing he'd paid a bunch of money for supplies, because he had already written a fraudulent claim for a large tax refund for his business, and the tax office wrote back asking for evidence of this expenditure. That was his last chance to say "Oops, that was er... a mistake" and maybe get a fine, once he decided "I'll just forge the paperwork" he was doomed to go to prison.
Item 1 on the court's agenda was to tell Companies House that the guilty man must not direct any companies. Never (unless a successful application is made to reverse this, which is unlikely) can this man serve as director or secretary of any type of company again. In his family business this means a son will now run the company - why? Because the freedom to direct a company is not essential and we evidently can't trust this guy to do so because he purposefully lied to the tax authorities. He doesn't need to "earn" that back, let somebody trustworthy do it instead.
The guy also got some months of prison time, after the court had reassured itself that this would not leave any dependants destitute -- no point sending one guy to prison only to have his kids turn to crime to get food right? But the fervent hope of the court is that this results in him being _reformed_ and no longer breaking the law.
We can also disqualify people who commit electoral fraud from participating in elections. Oh two government employees conspired to stuff a ballot for a $500 pay off? They're not just going to prison for a little while, they will also have a lifetime ban on standing as candidate in any election and from participating in any way, including as an ordinary voter. No more democracy for you motherfucker.
As to "eternal" punishment, in countries that don't have the Death Penalty (all of Europe for example) what else should we do with unrepentant murderers? Anders Breivik for example still expresses the belief that murdering a bunch of young volunteers was the right thing to do. We obviously can't be like "OK Anders, you've served your time, don't kill anybody else" because that's exactly what he'll do. So he will most likely spend the rest of his life in a cell - periodically psychologists will assess him, say nope he's still dangerous, and he'll stay behind bars.