Izzet Affinity is a slow artifact-ramp deck built around Urza's Saga into Karn, the Great Creator, The One Ring, and Force of Will/Force of Negation for protection, so you have time to assemble your combo but need to fight through counterspells. Talon Gates of Madara comes in as land-for-land upgrades that also add colorless or any-color mana to help cast Infernal Tutor or Beseech the Mirror through their countermagic. The extra Cabal Therapy strips a Force of Will or Force of Negation before you commit to your turn. Cabal Ritual is a weaker mana accelerant here since their game plan is grindy rather than fast, so a little more resilience against countermagic outweighs raw speed.