DRX has crazy set plays and executes. However, some of them can be anti stratted by an average silver once you watch the VODs.
I think the best example would be ZETA vs DRX at Iceland the previous year. The first ZETA vs DRX game was a wipeout from DRX. ZETA could not even get more than 10 rounds on both maps combined?
However the second time, ZETA genuinely looked like the better-prepped team. I will give one example: On Icebox A site exec on Attack, Rb on sage would wall nest and plant the spike on top.
It is hard to counter since its not the most common spike plant stop and even if you know lineups, the wall stops util from reaching Rb leading to a safe plant.
On the other hand, when they replayed on Icebox, ZETA had lineups prepped, for the exact sage wall that Rb uses. They bounced off different ways and therefore managed to reach Rb.
I cannot count how many times DRX were denied a spike plant. Just because of the fact that they were running this execution even in the second game against ZETA. I even saw Rb die instant as soon as he planted the spike because ZETA would viper molly and Sova would shock dart simultaneously scoring an instant kill on the planted which is hard to dodge.
DRX relies very heavily on pre-calculated strats, that probably their coaches cook up. It almost feels like they are just drilling rounds in different scenarios in pro matches. That would still work normally but Riot releases broken new agents or changes the meta every event, therefore, DRX cannot build up experience as well as a team in lets say CSGO's static meta would build up.
I think it mostly comes down to the IGL. I don't feel like Stax does the "Hey those guys are doing A and therefore we should do X to counter it". Rather DRX goes more on the line of "They figured out our plan A, its time to do plan B that we practiced in scrims." even though plan B might have the same holes as plan A does. Just switching up set plays won't work. You need solid mid-round IGLing.
I don't know where I heard it from but a pro player said this once on a team:
A tier 2 team adapts to what the opponent team is doing after the game is already over or at best after 6-10 rounds.
A tier 1 team playing at the highest level tournaments can adapt in the next round/2-3 rounds at max.
The absolute top teams in the world can adapt mid-round, right then and there.
All that being said, you cannot deny DRX is improving from the international experience. They are not dumb. They can beat any team in the world without overexxagaration. They have started to make deeper runs and the day is not far away when they actually lift a trophy. They always come in as strong contenders for the title.