> Have you considered that maybe there is a reason that otherwise different societies have almost universally evolved to impose harsh punishments?

The linked article suggests that this sentiment actually comes and goes historically.

How do you know that in the long term, we're not evolving in the opposite direction, to not impose harsh punishments?

One of the reasons why punishments used to be so harsh in the past was that enforcement was very inconsistent. In premodern times, it might take a lot of individual crimes before a repeat offender was caught. Given that most crime tends to be committed - even today - by a small, but prodigiously active subset of the general population, once someone was caught stealing, robbing or murdering, there was a tacit assumption that it was a career criminal. Who, in case of a light punishment, would go on stealing, robbing and murdering his peers for the next ten years or so.

Which is why permanent incapacitation - mostly by the sword or the gallows, but sometimes by being sent on the galleys, into the mines etc., which was scarcely more survivable than an actual execution, only that it took much longer to die - was the usual judicial punishment. At the very least, the criminal was branded so that he would be instantly recognizable forever.

Nowadays, the police has a lot more tech at its disposal. If it is willing to do so and financed to do so, it can catch basically any criminal it wants to. That is why our laws no longer resemble the Bloody Code of early modern Britain.

https://en.wikipedia.org/wiki/Bloody_Code

That's a good point, but AIUI those harsh provisions weren't even enforced very strictly. Similar to modern plea bargaining, there were many ways to reduce the punishment one would actually end up getting. I believe that David Friedman describes these mechanisms in quite some detail in his work on unusual legal systems.