An example of balance in my eyes:Garen

Okay, first thing first, fuck garen's true damage ult, we can ALL agree on that, right? Secondly, his silence does shut down a TON of champions(namely all casters) Thirdly, he has natural scaling(will explain later but it's an amazing part of the game) But he has counterplay

Okay, the ult's counterplay is nullified by it's true damage execute IF you are the villian. On top of this, villians take a flat 1% of their max hp as true damage, which is on top of the physical damage he deals already. And as such, building pure tank vs garen wont work if you kill anyone besides garen, this creates a VERY passive laning phase that is a farm-fest, as trading is difficult because...

His q's got amazing power built into it, letting him disregard slows(read:Nasus) and gain increased damage+a silence, which have historically no counterplay. The caveat of this move however, is that it is his only means of engaging opponents; it's only a movespeed buff, so it has massive counterplay. But again, shuts down certain champions, nasus, trundle, and mini gnar coming to mind. This doesn't affect champions without slows, so it's not op, as you can use knockbacks like jayce e, alistar headbutt, and vayne e to get him off you. The silence deals with these champions(except ali) Silences completely negate any abilities your opponent has until its duration ends, bar a few abilities, tryndamere, heimerdinger, karma, olaf, and alistar ultimates, and oranges. All other abilities are stopped, and must fight garen using autoattacks, which is difficult due to...

His natural scaling is an amazing thing, and hidden in it's power, what is it though? Natural scalings are those which are isolated from the events of the game, and contain either a tool which scale off opponents, such as veigar ult, irelia passive, fiora's passive, vayne w, and so forth. These types allow counterplay, veigar ult is countered by magic pen or attack damage(magic pen artificially increases ap); irelia is unable to as easily deal with one cc packed champ as 5 of them; fiora's is based on positioning, vayne's is stopped by attack speed slows or low hp, high armor. There are also time-based natural scalings, which have no prerequisites which bar efficiency. Examples being Cassiopeia passive, zilean passive, and a few more(long post, and want to shorten a bit) These abilities often require long time frames to become noticeable, Cassiopeia's being a free hat in bonus ap, zilean's being a bank of xp, increasing over time. These are a time-based counter, win fast, they won't be an issue, otherwise...bad things

And then there are interactive natural scalings, which are ENTIRELY based off of your performance in the game, and often have entire champions balanced around this. Examples being: veigar q, nasus q, thresh passive, bard passive, sion w passive, and garen w passive. All of these require massive amounts of farm until powerful, except for thresh, who only needs souls, but has the lowest scaling. Garen's w increases his armor and magic resist for every minion he kills, up to 30 armor. This is massive when looking at his passive's health-based scaling, and the effective hp he gains from each individual minion kill is immense. Now for the last part

His counterplay is seen in high-elo games, where kills are MUCH less common, meaning he could possibly never have a villian, and this is his problem in lower elo, players don't attempt to save theirselves by doing everything in their power, and kills are abundant. Conversely, his power is lowered in high elo due to the skill these players have, they will keep garen off their backline with occasional cc, while killing the opponents or forcing them to flee.

Its the same reason kat isnt competitive, she loses efficiency at high elos