There's no conspiracy here. Smollett lawyered up. Geragos is no joke. A guilty verdict would have been the official end of Smollett's career, so he went all-in on his denial and defense by hiring a renowned shark.
The high profile nature of the case coupled with the police commissioner's monumentally stupid press conference tainted any potential jury pool. Geragos would have argued for change of venue and the prosecution's only argument to oppose would have been that the case was so ridiculously public that he couldn't get a fair trial anywhere. That's bad.
Now add to that that their star witnesses were the perpetrators, with every reason to lie. That's pretty much reasonable doubt right there. Everyone involved would have looked stupid pursuing a trial. It wouldn't have looked good for anyone, and for what? Given all those hurdles it's doubtful they would have even pushed for jail time, and once you've conceded that the only positive outcome is to get financial restitution and they're going after that regardless.
That press conference held by the police was a monumental mistake that cost them any chance at a conviction. Without it, the public nature of the investigation would have been seen as Smollett's fault -- he was the one pushing the narrative, talking about it on stage, going on GMA, etc. The police presser completely reversed that, handing them a case and basically a victory.
Hes 100% guilty, no question, and that's why you don't try cases in the press. They should have held the grand jury, shut the fuck up, and prosecuted him like anyone else. They had him cold and completely fucked it up.