The Preseason overhauls are not really something that should -ever- happen to a game like this
I feel like when you make a TON of dramatic changes to the way the game in played, all in one patch especially, it nullifies all previous balancing changes you've made in the past.
Preseason changes are like a hard reset on the overall balance of the game. The devs spend so much time patch by patch adjusting champions because of this or that to make the game more fair and then suddenly you just flip the monopoly board. All the pieces come crashing down in disarray and there is no balance.
You get champions with 57% winrate in diamond and competitive picks tighten up from 50% of the champion pool to 15-20%.. Diversity is fucked because a select few champions are just so much better for winning the game than other champions. Riot decides to keep all the champions they (for whatever arbitrary reason) that they want in the game. Lots of champions suck but the balance team is thinking: 'Lets give maokai mr per level' and suddenly hes in EVERY SINGLE PRO GAME.
Hey riot, how bout you do the best you can to make ALL of the champions viable... and then KEEP IT THAT WAY. No more tier 1, tier 2, tier 3, tier 4, tier 5. That's bullshit. If a champion sucks to the point where it cant be played in competitive, or a champ is so good it's the ONLY pick in competitive, MAKE CHANGES.
Riot doesn't like udyr. Udyr gets nerfed.. he's still 'too good'. HE GETS NERFED AGAIN. Where are the follow up ekko nerfs? WHERE ARE THE MAOKAI NERFS? WHERE ARE THE NERFS? GET YA BOY MORELLO IN HERE WITH THA BAT. KINDREDS BEEN GIVIN HIM AN UGLY LOOK FOR A LONG ASS TIME, AND HE SHOULD PROLLY TAKE A FEW SWINGS.
If champion diversity is GOOD, and you continually introduce new champions, maybe a new item occasionally, YOU WONT HAVE TO CHANGE DEATH TIMERS/TURRET HP/GAME LENGTH/DRAGON. If you keep the pool diverse, balance will follow, and the game will feel fresh.
tl;dr: Preseason changes are loads of completely unnecessary bullshit that make this game worse.
