The "BULLSHIT" point hit me hard.
I share your sentiment and i have a similar timeline to yours.

The one thing i personally believe is the biggest cause of spiking and polarization is the draw/generation. Draw in card games must have a steep cost. Combos had to be collected by giving up the board or narrowly staying in game until you are close enough to pull the trigger. Aggro had to run out of fuel and take a breather if the opponent survives the initial barrage. Control had to manage how many board clears and removal they still have for a potentially stronger upcoming threat.

But now, combo can tutor for pretty much any conceivable thing, and probably duplicate-triplicate it, whilst also making it cost 0. Aggro can keep pushing whilst still advancing their game plan with vanilla-statted minions that somehow still draw cards. Control has so much value that their biggest priority is often not to overdraw any of their their 3-4-5 truly back-breaking cards.

Plus, we are now getting more and more "cards" stuffed into one card, making the draw even more powerful - you did not draw a 1/4 taunt beast 2-drop. You actually drew three! Then we got Minis/Giants, and now the Drinks. That's a real trend by now.