Majority of balance problems

Most of those problems come from one thing. Damage. It is simply too high. If a champion has to do only one rotation of combo to kill you then it is something really weird. Also killing people without having to outplay them in any way, just because you deal a lot of damage is not fun.

While playing assassins I noticed that unfortunatelly most of the time, the basic combo can oneshot everybody anyways. You don't need to try anymore.

Tanks are also doing a lot of damage, that is not as necessary for them. They are not fulfilling their roles as protectors and engage, they do the same things as brusers, just are worse than them.

Mages also deal too much damage, but because of assassins they are not played that often.

ADC are doing too much of damage as well but they get oneshot by assassins all the time and 2 assassins in enemy team can basically delete the adc in every teamfight.

Support is the role that went under the biggest change. What happened to supports being the ones to heal and protect you? Now you heal yourself while doing damage and shielding yourself and support's role is just to be the second mage or tank.

In jungle tanks and other roles than assassins basically don't exist anymore. You just have to pick an assassin. The only real alternatives are Xin and Graves. The rest is like giving free lp to the enemy, if he picks an assassin and is somewhat familiar with his character.

I really think that damage should overall be reduced and that the traditional role of supports should be restored. Gravious woulds is not worth altering the whole role just to keep it in the game.