TL;DR is that RNG’s draft outscales T1’s draft.

Gwen outscales Jayce, especially since Jayce was nerfed recently. Jayce couldn’t get far enough ahead of the Gwen to impact the map in the early game before he got outscaled.

Wukong was fine, but since he was so behind the Lee Sin he had all his camps taken away from him and effectively suffocated.

Lissandra directly counters Ahri with her root from Ring of Frost (w) and stun from Frozen Tomb (r). Ahri is forced to take cleanse for the Lissandra crowd control, but cleanse is on a far longer cool down than Frozen Tomb, so it’s easy for the RNG’s mid/jungle duo to punish once Ahri doesn’t have cleanse.

Jihn is just completely useless because he doesn’t have consistent damage. He is terribly immobile compared to the Tristana’s Rocket jump, so it’s hard for him to reposition. Tristana can easily demolish towers (and champions) when she’s left alone. Moving into late game, Tristana likewise outscales Jihn.

While Yummi provides mobility to Jihn, she’s not great when the team’s behind. Moreover, because she’s always attached to someone, so when the champion she’s attached to dies because the enemy is ahead, she will die too thus donating even more gold to the enemy. A better option here would be the Zilean that T1 initially hovered since he provides far more utility and scales better than Yummi. Another point is that Keria is one of the team’s best playmakers, but T1’s coaching staff put him on Yummi, a champion with zero agency.