What's going on with Riven?
So I used to be pretty decent at Riven, I could manage to carry games 1v5 but these days I can barely get a lead even if I win my lane. I'm just curious has the playerbase gotten that much better? Or is Riven just weaker in comparison to champions like Irelia or the new Akali? I remember in seasons 2 and 3 Riven was so strong and she felt GOOD to play. I don't want to keep playing Riven if all I'm going to do is hold my team back. Also keep in mind I know she can be strong in some situations, and I know in the right hands she is a monster(Viper, BoxBox, etc...). But can someone just attempt to explain to me if all of this is in my head or did the game just change and Riven isn't where she used to be? Thanks in advance.

Also what do you guys build for Riven because that may be the core of my problem.