[Question] What exactly did FTX do wrong?

Now that SBF has been actually convicted I think it might be good to have a simple explanation here of what he and rest of the EA-affiliated FTX leadership did.

[Edit: Hopefully I haven’t accidentally given the impression that I don’t think FTX did anything wrong (this question seems to have been downvoted). I absolutely believe they did wrong and committed fraud. I’m just not sure what it is that they did]

This is one of those times where Google has proved surprisingly useless. I see that he’s been convicted of several counts of fraud, but the only explanation I’ve managed to piece together is this:

Alameda held a load of FTT and borrowed from customer deposits held by FTX. People tried to withdraw their deposits after it came out that Alameda held so much FTT, but FTX couldn’t pay out because Alameda couldn’t give back the customer funds it had borrowed.

I get the impression that Alameda sneakily holding loads of FTT was very bad, but not illegal, is this right? I guess this is bad because the value of FTT is linked to the value of Alameda and vice-versa so it looks like their assets give them more security if something goes wrong than they actually do, although I only just figured that out.

As for Alameda borrowing customer deposits—I don’t understand any of this. What were the rules around lending out customer deposits? What made the lending out to Alameda fraudulent? This seems like THE key thing that FTX did wrong and I just can’t find a basic explanation of what the crime was.

Would greatly appreciate any clarification!

[Edit 2: could someone who is downvoting briefly mention why they are doing so? I’m a little confused as to why this got such bad reception]