There are a lot of reasons why many people are unsatisfied with the state of the game. Some may say that Riot's creativity dissapeared long ago; others may say such thing never existed, but one thing that almost everyone agrees is that Riot has fallen in love with Damage.
Yes, Damage, one of the most important factors in the game. But hear me when I say "one" because even though it is really important, it is not the only thing that decides wether you are successful or not. However, Riot Games seems to be inclined towards damage for some "view-satisfactory" reasons. (Viewers>Players, for Riot).
Therefore if a champion dies too fast, they add damage. A champion lacks mobility? Add damage. Flashy champion not used in LCS? Add MORE damage. But Riot does not seem able to understand that most assasins (original ones, even though today many other champs can take such role DUE TO RIOT) aren't used in LCS because all they do is that. DAMAGE. But damage is not everything, especially in LCS teams where they value more utility because they refuse to take the 1 vs 1 mentality that Riot is trying to create in the game and they understand that having utility abilities which complement with their allies is important.
Champions with a lot of damage in their kits aren't used not because they lack damage or mobility, but because they don't contribute with anything besides damage, and damage is again not everything. If you want an assasin to be picked in LCS, you should first return that champion to its original concept (high risk, high reward) which means lowering part of their damage until they are able to kill you from 100% only if they do the Whole combo correctly. They can in exchange add some utility to the champion which can be exchange for an unnecessary dash (refering to champions with 2 or 3 dashes when 1 is already good) and give them some power other than kill enemy in 1 second or die in 1 second.
Another thing that Riot is doing is giving inmmobile champion lots of stats increasingly just because they are kited by ranged laners (for example in top). Let's take Dr. Mundo for example which have had problems being kited and therefore Riot's decision was to overload him with stats. This was also influence by Riot's lack of creativity and pasion towards damage. This made 3 possible scenarios which nobody enjoys and only spread toxicity.
Scenario #1: Dr Mundo gets kited into oblivion.
Scenario #2: Dr. Mundo somehow gets near ranged champion and deletes it in to 2 to 3 seconds.
Scenario #3: Dr. Mundo faces a melee top laner which is not an early game bully and faces the consequences of Dr. Mundo being overstated because Riot couldn't find a better solution to make him do better against ranged champions.
If you want Dr. Mundo to be able to face and somewhat have a way to respond to ranged poke, you could make Dr. Mundo's Q hit and pass through minions, and make the range a little bit longer, so that he can actually answer to Ranged champions if he predicts correctly while also lowering some of his Q's damage. This would be better than giving Mundo excesive stats and leaving him unable to answer ranged and eating all the poke for free.
All solutions aren't related to Damage, but you, Riot, are using Damage as your only solution.