Abacha stole $4bn.
Nigeria has "recovered" $700 million of that in 21 years.
In other words, Nigeria has only recovered < 2 years worth of interest payments on Abacha's loot.
Let that sink in.
That's why you don't steal from your people and entrust the money to people who are smarter than you.
You're a mug.
That's $400bn invested in infrastructure and R&D that keeps them ahead of us.
So nobody gained anything except the Swiss.
You see why they think we are all stupid creatures?