I don't see how roughly 90% of those make the game easier to play
-Dragon got nerfed , used to give a ton of gold / exp
I don't see how you can see the changes to drakes doing anything BUT buffing dragon.
-Minions are worth less gold, just focus on getting the cannons
On the flipside, it's much easier to deny your enemy large amounts of gold by forcing them off of just one minion. In lane you have to intelligently fight around cannon minions.
-Red buff health regeneration added to the game
don't see how this made the game easier
-Mana costs were lowered, mana items made better / more abundant
you forgot that they changed Morellonomicon, AKA the "I never need to refill my mana bar" item.
-Complicated rune system removed making the game easier
there was nothing complex about the old rune system, other than learning to dodge noob trap runes. The current rune system is much more complex IMO because it forces you to think about what runes synergize with your champion effectively, which ones don't, and which runes fit your playstyle and which ones don't.