Proofs that damage burst has increased at least of 15% since season 5.

Comparing damage at same level and same amount of kills :

Talon lvl 4 vs zed lvl 4 : full combo comparison

Season 5 talon combo +1 supplement auto = around 50% of zed's life without the supplement auto = around 40% of zed's life

https://media.giphy.com/media/jV4vwYYU9quJKiHi3i/giphy.gif

Season 8 full combo without auto : around 55% of zed life without any supplement auto.

https://media.giphy.com/media/1jW9LVqEklB8T9aDi9/giphy.gif

lvl 6 Zed vs lvl 6 Akali 2 shuriken damage :

Season 5 around 25% of akali's life :

https://media.giphy.com/media/7dLxWAAjmD3K8zZbbY/giphy.gif

season 6 around 40% of akali's life :

https://media.giphy.com/media/1xjX8XYIFZW8u8gDuu/giphy.gif

those are just some few examples and there are a lot more. The damage burst even goes even further with higher levels as it exponentially raises...

The Damage per Second increased Too much Aka Burst is stronger and quicker than ever. Damage stay the same because your health bar has not changed a lot since s5. Only Burst and speed of the burst has increased.

So riot here is the issue with your game..