Is there anything Riot has done in the past 3 years that was good? Just quit.
I did and let me tell you, I've had a blast playing other games. It sucks that League is a shell of what it was, but it's just the truth. Unless you are new to the game and joined after it became a bastard shell of it's former self you are likely pretty unhappy with that's happened to the game over the past 3 years.
Stop complaining about it, and just talk with your feet. Ask your friends to do the same. Maybe if Riot sees players leaving in mass they might actually change some shit. Make your own posts, toss up some Youtube videos, put shit on Reddit. Do whatever you do, but be heard.
Just bitching about it on the forums isn't going to change their minds.