Even if, hypothetically, no crime were to occur, with enough customers and employees, at least a few will be disgruntled, and willing to lie, exaggerate, delude themselves, or misunderstand what's happening.
The result is that expose hit pieces are easy enough to craft against anyone powerful enough. The key question is always about how common improper behavior is, who knows about it, under what cultural standards it is considered improper, etc.
I'm not trying to undermine the underlying point: Most people who got very rich engaged in at least some corruption to do it. But a key word there is 'most.' Virtually all are possible to publicly discredit, and it's important to read such pieces carefully.
Some of those are illegal, and some merely unethical. In some cases, that aligns with corporate interests (more sales!). In some cases, it undermines corporate interests (bad reputation). In some cases, the person on the top quietly supports bad behavior, and in some cases, they have just a hard time stopping it.
It's often quite hard to tell all of those apart. But we haven't really found a way to avoid at least some of those happening in any organization above, say, a few hundred people. Even at a hundred people, it's tough.
One of the underemphasized advantages startups can have over big companies is pretty good alignment and protection against this sort of stuff. Everyone knows each other, and works as a genuine team.
Have any children inherited that level of wealth?
This arbitrary and dangerous thinking.
But if you really feel like it by all means start looking closely at as many billionaires as you can identify and prove that each of their gains were ill-gotten.
Just please avoid the generalization.
There are over 2000 billionaires in the world, and rich people often pay extra for privacy. Learning about all of them isn't a small feat. It's good and proper to have public discussion about such questions before entering research.
What if someone wins the lottery (after many roll overs)?
At what point do they become criminal sociopaths? When they cross the billion threshold? USD or local currency?