> anticompetitive practices, and the no poach agreement with Apple, Adobe, and Intel, off the top of my head.

Almost all of those were done (temporarily) well after the fortunes were made.

Any examples you'd find I'd bet 95-99% were either the result of subsequent monopoly or as a result of government intervention either directly/indirectly benefiting them.

The 1-5% which weren't were likely punished. As the examples you mentioned were...

Sokols alleged insider trading involved stealing from Buffett. The Gen-Re execs weren’t found guilty, they plead guilty to minor counts of “fraud” after 12 years of grinding prosecutions and after they won several trials. Their crime was claiming to not know that AIG was going to use a profitable insurance contract Gen Re sold it to commit fraud. Gen Re never committed any fraud itself.

And Buffett was the richest man in the world well before either of these incidents.

> can be seen as crime by some people

That doesn't make it a crime. But it does make those people less credible.