Google posted a topic of infinite loop combos showing up more in game play.
Enduring Renewal with Ornithopter and Ashnods Alter was an infinite mana generator all the way back to Iceage set. Point is infinite combo's have basically always been there. Making it be at least 3 to 4 cards to complete the loop was the trick. Gave the other player time to destroy one part of the loop to stay alive. More cards started to have the "end of turn" effect to limit loops. 2 card infinite loops is too powerful and the blame lies with the developers for letting that happen.
More people would use the "venture into the dungeon" if it was more powerful. An angel will straight up win the game if you just have more life than you started with (example of power difference). How bought venture into the dungeon 10 times and your opponent loses the game or you win. That would be threatening enough to pay attention to during game play. Look how powerful the ultimatum cards are (high casting cost being the only draw back).