I think you want mutually incompatible things.
1)If you want to know the full facts of what he did and how the court case went you'd need to do more than read the wikipedia page.
https://www.courtlistener.com/docket/66631291/united-states-... is the full docket of original source materials if you want to find out for yourself.
It was a complex case so there are a lot of documents etc but all the actual facts of what happened in the case are there. IF you want to read who said what, what all the documents to and from the judge were etc, go nuts.
2)If you want a simplified version, it's basically what a sibling said. FTX was an exchange. That's supposed to look after people's assets that they place in custody so they can use those assets for investments. Alameda was a hedge fund. It's supposed to use investor's assets to make investments. Instead, FTX loaned customer assets to Alameda to invest. That in and of itself is no bueno right off the bat. It's a violation of the contract with customers when they deposit and is improper use of customer funds.
Secondly they kind of spent 8bn of the customer assets. On getting celeb endorsement, private jets, parties, conferences with big-wig speakers, real estate and other stuff. That's called stealing, and is also considered a no-no.
Third there were campaign finance violations. He took customer money and improperly used various front individuals and companies to make political donations. That's not legal.
Fourth he seems to have violated money-laundering laws either by part of the third thing or in some other way.
Fifth there was probably also wire fraud because everything is wire fraud and also because they actually had a Telegram Chat channel called "wire fraud" (they say irony is dead).
That's probably not all but it's enough.