The Root of ALL of League's Current Problems

is Lifesteal. Including other autoattack-based sustain. (that implies that the sustain is not gated by something like mana or limited charges)

First, let's consider how a game's state becomes when Lifesteal is strong:

Defining Lifesteal: Lifesteal allows regeneration of HP without any resources, the only "risk" being that the user needs to be in range of some enemy unit to attack. The counterplay to this, then, is to attack the lifesteal user when they enter range to heal.

The problem with this is the fact that when Lifesteal is STRONG, they heal enough that Poke is negligible and the "attack them when they enter range" aspect of it becomes "try to kill them when they enter range or don't bother", because if you didn't outright kill them, they're going to heal all that damage back.

In short, Strong Lifesteal = Poke negated = "Risk" of Lifesteal negated if the user can't be killed.

This leads to the need for burst damage that can kill the Lifesteal user before they can escape [then heal up] or heal the damage back in-combat. In other words, without sufficient burst damage, that Lifesteal user is not going down.

So what naturally happens then is that people start to notice, if both sides have Lifesteal users (who tend to be rather squishy overall), but one side also has the burst to DELETE one of them, the team of 5 is a lot more likely to win a fight than the team of 4. Or group of 4 vs a group of 3. Etc.

So then people opt into using Champions and Items that do exactly that. Blow targets up.

What if they can't? Well now they're useless because everyone that survives is just going to heal back up.

To sum this section up, Strong Lifesteal -> Strong Burst Favored -> Those that can't Burst are pretty much useless.

Now we have 2 Things left to go over: Tanks / Supports, and The Champs that don't do enough Burst to be relevant or rely on Poke damage in a strong Lifesteal environment.

First, Tanks and Supports.

Obviously, when Burst is favored because anyone NOT DEAD can heal right back up, everyone squishy becomes a target. Not just the ADC, but the melee skirmisher, the enchanter support, the mage, etc.

So then it becomes obvious that if a certain team member can be targeted and NOT die, that is also a huge advantage, especially if the opponent's targeted member DID die.

Enter the Tanks, who can CC, take damage, and survive long enough to contribute more than the deleted squishy, and the Supports with kits / items that help other squishies survive.

The above, when acting appropriately, have the ability to prevent their damage dealers survive an encounter with Burst, thereby allowing them to recover through Lifesteal or other form of healing. If at any point in time, this happens while an enemy team member is killed by allied Burst, then now there is again a number advantage, so Tanks and Supports become very strong and influential.

So far, Strong Lifesteal -> Need Burst -> Need to help squishy teammates Survive Burst -> Tanks and Supports favored and highly influential in match outcomes.

So what about the Champs that DON'T fit into any of this? They don't use Lifesteal to heal while dealing damage, they don't do such high burst that weaker targets simply disappear, and they don't survive enemy targeting easily or contribute by helping allies survive..

They're useless for the most part. And if they're useless, they need to be buffed.

That's what happened.

So now, even champs that didn't need Burst can blow squishies up, Assassins that couldn't deal enough Burst to blow through a squishy's HP when there's a Support / Tank helping out were buffed, Mages and other Champs that relied more on DoT or sustained Damage were buffed, Champs that rely on Poking were buffed, and now EVERYONE does oppressive amounts of damage. New champ? They'd better be able to fit in. Or due to the above reasons, they're going to be useless. Then buffed.

Summary: Strong Lifesteal -> Need Burst -> Need to help Survive Burst -> Tanks / Supports with shielding / CC / healing strong -> Need even MORE damage -> Damage buffed over and over

**If Lifesteal were to be nerfed, you wouldn't need such high burst, wouldn't need such oppressive levels of damage everywhere, wouldn't need tanks or supports to be so strong, and there you go. The game can be balanced again without so many matches being snowballing festivals of blowing enemies up over and over. ** Have a good day.