That’s because G2 doesn’t rely and cater their game to the Gold lead. I feel like there is this misconception that a team “shouldn’t” fight while down in gold and they “shouldn’t” be proactive when down in gold. That thought process opens the door for the gold lead to just balloon because a team isn’t doing anything about it.
Every time SKT got Baron, G2 attacked them and voided it. Most teams would have Just turtled until the buff was gone, but G2 didn’t care and fought them anyway. I think SKT lost those fights because they didn’t expect G2 to attack them because they had Baron! It was a glorious display of saying “screw your gold lead!”
I especially loved it in game 3 when SKT had Baron and a lead, and G2 just pushed into their base and took it... I imagine SKT went back to their room after that and was like... “can they do that? Are they allowed to do that?”