Although Russia is basically a dictatorship at this point, and courts aren't fully impartial, there's still place for maneuvers with good lawyers finding loopholes in the law - judges can't simply ignore the law outright, hence some limited success in courts. Usually it's about appealing to procedural mistakes which overturns cases. For example, a week ago a political case against a popular Youtuber was closed because of the statute of limitations - his "crime" happened a long time ago and so the government can't prosecute him anymore. However, if a case is initiated by Kremlin itself (not one of the less powerful agencies) then you'll get jailed no matter what (they can leverage FSB to fabricate evidence).