By dropping the charges she will get them testify against Trump who she really wants. I’d be willing to bet that is a part of these plea deals.
I still think the case is crap but it doesn’t matter. Her ultimate goal is to stop him from getting elected by hindering his campaign. She can likely find a jury in Fulton County to get a conviction, then the appeals will take years and I think it will, ultimately, get overturned. But the Dems have their talking points and that’s all that matters.
Had Trump not run, I don’t think most of these cases would even be brought at all. It’s all just election theater.