I feel the problem is snowballing
Most champions are balanced if you know who your playing or who your going against. MOST champions.
I feel the problem is snowballing, giving that unfair advantage to a player who is killing and getting items and levels much faster. Only few champions can really counter that stuff well, and i believe if riot somehow got rid of snowballing, things might be easier and we would have a better time facing each other in combat.
I understand many want to have the option to solo carry if their team isn't doing good though. I understand there are trolls and it sucks, but at least you could have a more or less equal chance of defeating your opponent.
I also believe they should increase health of all these champions a bunch, having the ability to survive multiple combos or damage will keep this from turning into a 5 second "call of duty" battle. This would also make farming feel safer for those champions who like late game. They wouldn't die so quick and they could be much more viable than they are now.
I dont know about this, but in my opinion, assassins should be there to finish off low health opponents like securing a kill. Something like having abilitys that damage based off of remaining health or something. That would make them more of a poke and prod champion i know, but at least you would have a upper hand with most of your health.
Changes like these, not that i was perfect at constructing these ideas, would benefit the game a lot i believe. It would even give you more space to balance things out with champions instead of setting damage so high that anyone can win if they shoot their ability fast enough. I don't want you to balance champions by doing THAT!
I feel like riot wont visit the boards anyway, much less look at this post. SO, i leave this with you guys, see how it feels.
(Edit) They should also work on this MMR. Face it, you have higher chances of being outplayed by someone with more time and skill put into the champion. Thats why YOU need to be paired with others like you! If riot could work that out a little more that would be awesome.