A Different Thought - Tanks and Bruisers

The thought is: Could the decrease in overall damage in the game actually be a contributing factor to the replacement of tanks with bruisers?

Overall, compared to Season 1/2 and before, the damage dealt by AD carries and AP mages is lower. There used to be a lot more penetration and damage in the offensive tree (10% bonus Crit Damage, 10% and 6 flat for Armor, 10% for MR), ADC items used to have more damage increasing stats (BT 100 AD, LW 40% Pen (and ADC seldomly build flat Pen after the penetration changes), PD 55% AS) and the same for AP mage items (155 AP Deathcap). Also, especially in the AD carry role, there was a massive preference shift for a strong mid-game (Ezreal, Corki, Graves back then), who bring less damage in the later stages.

Now, with less damage from two sources, it might raise a necessity for damage from another source. And the most logical choice for this is (or used to be) the top lane, since this is the third high-gold role in the game. Resulting in pure tanks, able to function on lower gold values, becoming relegated to the jungle role. In the next strike, the cost of defensive stats was increased, and the cost of offense decreased. This weakened the already gold-starved pure tanks even further.

Now, I am not saying that the damage decrease is the only, or even main factor in the transition from tanks to bruisers. However, it is probably a contributing factor.