Discussion about Balance and "the meta"

This game is not balanced. Nobody disputes this. Infact, that is where the term "meta" comes from, the imbalance of the champions that leads to the "top tier" picks. Everyone knows that you cannot perfectly balance a game where everyone does not get the same tools to succeed. However, I feel that this is being used as an excuse to have some champions be much, much more powerful than their counterparts, and not just slightly more powerful as some people would have us believe.

A great example of this would be Tristana. I don't think anyone will argue with the fact that she is incredibly strong late game. But she is also quite strong in the earlier stages of the game, only suffering from a 5-10 minute power lull in the mid game, one that can easily be overcome simply by abusing her strong early game and then playing passively. She has some of the highest sustained damage, and in reality, burst damage in the game. While at the same time she is incredibly safe (safer than Ezreal while at the same time having better sustain, burst and utility) as well as having more gap closers than any other adc in the game. Her ability to dominate a teamfight is unrivaled. Champions are supposed to have clear, defined weaknesses that actually matter. Sure, in theory Tristana is squishy. but this doesn't matter because due to her range and escape tools, you can never actually squish her, certainly not reliably. Even compared to Ezreal, who is supposed to be super safe and pays a huge price for his safety, she is much, much harder to kill, and has better damage and utility.

Its not that im asking for perfect balance, its that having a champion that is quite literally better in every way than another is just pidgeon holeing people into picks. I submit that if riot wants to make certain champions so vastly superior to others, that they should just pick champions for me. for example, if i'm playing ranked and the enemy ad carry picks tristana, the game should just ask me if i want to play Kogmaw, twitch OR xayah into it, since they are the only picks that stand a chance at putting up a fight for a tristana.

I could go on and on listing champions and discussing this type of thing, but I think I have gotten my point across, which is simply: Why are certain champions two to three times better than others??? Or another way of putting it, on a power level scale of 1-10, why are some champions a 3 and others are 10s? why cant we balance the game so that its LESS of a gap? One that can actually be surpassed via the use of skill? I'm not saying it doesn't take some level of skill to play Tristana. What I am saying is that when someone of a certain skill level plays tristana, it negates the opposing player's skill. Therefore effectively making the game a power grab first and foremost in champion selection, and less about actual play skill.