I think part of the problem is that most people think you just mash qwe qwe qwe after hitting R, without understanding how to time abilities to minimize W's CD and spellweave in the process (and of course never activate Seraph's). It definitely takes practice and conscious effort.
I'm against dumbing down champions to make them more approachable because it makes playing them less rewarding, and usually makes combos and playstyle very linear and homogenized. I know many people have asked for this, but a sandbox mode to practice combos would GREATLY benefit those wishing to learn difficult champions. No serious 1v1 fighting game lacks this mode for a very good reason. It allows people to work on and improve a specific skill for as long as they like without having to waste time starting matches over and over and over or hurting teammates. I know MOBAs are born from RTS, and RTS games rarely have a sandbox option, but I think most MOBAs have more in common with 3d fighting games than RTS when it comes to combat.
Even a few Riot videos highlighting the mechanics for difficult champions would go a long way for many, since most don't bother to look up non-LCS replays. I think if you guys did maybe half-hour video for difficult champions, explaining the mechanics, pros/cons, laning phases, etc., it'd be easier and more beneficial than rebalancing.
Great players are going to do their homework and figure out back timing and item advantages vs. each matchup, how far it's safe to push against each jungler, and so on. Most players don't figure out how much damage they can do in a full rotation, how much damage their enemy can do, etc. and this is all critical for playing Ryze well. Please don't hurt the players that have bothered to learn these things in favor of trying to make every champion viable for people who have been playing for a couple months.
If someone's able to consistently hard carry on Ryze, they've earned it. Garen, not so much. I want to have a champion's success and viability reflect the player's skill level, but I also think that the pools for plat+ should differ more than the currently do from bronze. If a champion's very strong at every skill level, that's boring. Give good players a tool for punishing those that have stuck to the easy champions that have almost no room for error. Learning curves make the game far more engaging and rewarding.