First off, this is not a rant. I do understand why you want to make the changes, but i don't understand the method behind it, i'd really like to know this.
Is the end result of these update really what you were looking for?
_**The juggernaut update**_
Skarner, Mordekaiser, Garen and Darius were up for changes. These were the prime targets of the update, everyone was excited, but you didn't just change them, you also added a bunch of new items like titanic hydra and dead mans plate. None of the above mentioned champions were very popular in competitive play before the change other than Darius from time to time. Looking at the end result, the only thing the update did was to make other champions stronger via the new items, like titanic hydra was used on more and more bruisers, be it juggernaut or not, until it finally got nerfed. And as of right now, we're back to square one where nobody plays Skarner, Morde, Garen or Darius in competitive play.
_**The Marksman update**_
Aimed at making marksmen more healthy for the game, a few champions were especially targeted once again, like Miss Fortune, Graves, Quinn and Kog'maw. They became too strong for a while, got nerfed, buffed, nerfed until nobody plays them once again, Graves might still be okay, but he's probably not gonna be for long. At the end of the day, once again, the ones befefiting the most from the marksmen update were unintended champions. Tanks got rid of last whisper (i mean the good one), which caused champions who don't usually go tank go mega tank, looking at you Ekko. Death's dance, just works better for bruisers than ADCs.
_**The Mid Update**_
Too soon to tell, but if history repeats itself, this is what's gonna happen, some mages will be too strong, have too much utility or something else, which causes them to be played a bunch. They will get nerfed/buffed and then ultimately nerfed again until nobody plays them and goes back to playing Yasuo, Diana, Ahri, Lux or Zed as usual. But who knows maybe the mid update is great.
I dont't know about you, but to me these updates creates a lot of chaos, they change so much about the game so fast, its hard to keep up and if the end result is not what you wanted then is it really worth it?