Turn timer vs animations
Due to alot of late game cards having long animations, the turn is wasted on pointlessly long animations. Also unable to queue other plays during said animations. By and large makes control decks unplayable. Boring aggro decks are only feesable.
I had a similar case where my opponent was playing Scute Swarm along with 2x of the artifact cards that let effects happen a 2nd time. I had a Soul Warden and Ajani Pridemate in play. So by the time they had about 80 Scute Swarm clones out, it was taking all the time to make the Swarm, then my Soul Warden gained a life, then my Ajani Pridemate got +1/+1. After the 3rd time this happened with many more Swarms in play already...it started to draw into MY timer because my opponent was completely out of time. In any case, my opponent could not even attack with their large force because it automatically ended their turn.