Some champions are quite strong when it comes to offense, but weak defensively. These champs are often called OP, but require a fair amount of knowledge to use them to their full potential. One wrong move can and will lead to failure.
Other champions have more balanced kits and don't shine in one area in particular on their own. These champions leave a lot of room for player skill to take over. They are fairly forgiving, but never underestimate one in the hands of an experienced player.
Then there are the champions who are more utility than anything else. They require an equal amount of knowledge and skill, but require more teamwork than the other two to reach their full potential. These are the champions who single handedly turn teamfights around and let your damage dealers do their work.
This is how I view it at least. You can easily view a lane matchup as a very meta favoring thing, but this is not a game of individual players. When viewed as the larger team game it is there is far more skill involved, particularly at higher levels when ward control and feinting come into play.