When you make things more rewarding you make players less risky.

What i mean by this is when you make the reward for going all in a kill more often than not players will simply never go for a trade unless itll be a kill. Because why would you try to fight your opponent when he can do just as much damage as you can if you can just wait until the right time and remove the counterplay.

This is provided by runes wards and the damage ramp.

Originally runes would give you small buffs making each trade have limited rewards. Because of this you would simply trade because the reward for trading was small but so was your opponents. Ironically making the reward better.

When you make junglers able to gank easier then you make players trying to fight worthless. Why would you ever try to trade if you can just wait for a gank to get a kill. This is what reducing wards does. It does not make players more willing to fight it only makes junglers have more dominance over the game.

The damage ramp basically does both of these things together throughout the game. If you have a choice to engage its probably not a good idea. Because you are putting yourself ahead of your team and losing a cc spell that could be used for stunning key targets; which is the only way to stop the damage ramp. This basically makes every single player have no reason to fight period unless they are already so far ahead it doesnt matter. They just wait for one side to make a mistake and hope for the best.

Then again why would you even try to fight when you could just hit bots that gave you more power anyway. Dragons being too powerful and turrets giving too much gold basically devalues the value of a kill. This actually makes playing like a pussy more rewarding since not going up for farm or kills is fine since youll get more value by other factors of the game.

TLDR: The high level of rewards in this game ironically makes everything less rewarding. Either you get the big bounty or you dont waste your time.