TSM Vs IMT game shows a potential flaw with Elder Dragon, and also current game design.
The game was over an hour long. But, the glaringly obvious outcome showed around 40 minutes. No one thought TSM could win anymore, which is accurate. Mechanically, both sides messed up here and there. Wiffed abilities, misjudged damage outputs, etc... Neither side really had the advantage champion wise either. Both teams scaled relatively well, had good trade and burst damage, safety champions., you name it. However, Dragon Soul + Elder Dragon buff more or less ended the game 20 or so minutes before it actually ended.
This is because teams are skilled enough to prolong a passive game, but cannot necessarily overturn the dragon soul buff entirely. I get tat it is designed to win games. However, if that is the case, then make it incontestable once acquired. But that isn't fun to watch or play in. However, neither is a game where one team more or less cant win, but the other team cant win quickly either. The buff is basically a "cant lose" buff. You will win eventually, but unlike Baron, it may take 10 or so more minutes because there is nothing with it to force a fight.
Taking Elder Dragon means the enemy team will not fight you head on unless they have the obvious advantage (which likely they never will have). However, The buff does nothing to give the holding team any way to force the fight either. Baron buffs minions, meaning teams naturally need to be close to each other to push or clear the wave. Elder just buffs personal stats and improves fighting capability.
So there is only 2 ways I see this getting addressed. Either buff the Elder Dragon buff to make it so oppressive the game ends once it is acquired. For example, make it so that every 3 auto attacks on the same target stuns the target champion for 1 second, and increase AA range by 250 ( 500 if melee). Or increase health regen by 1000% while making them immune to grievous wounds. Something so ridiculously OP that a team needs to be inting in order for them to lose.
Or, rework it to allow the opposing team a way back into the game. But this essentially defeats the purpose for its change in the first place.
Now granted, this is just one occurrence, but it does show it happening in a high skill level game. It could be just a fluke, but it may also happen again. We will have to see in time.