The World Cup is a marathon, not a sprint, so it’s not surprising that players with reasonable ambitions of making the later rounds are trying to save their strength. Tiebreaks may be harrowing, as Hikaru Nakamura and especially Alexander Grischuk know from yesterday’s adventures, but in general they take less energy than two full-blooded classical games on consecutive days. (They also give one more freedom in their opening choices, though that can of course cut both ways.)
So: the vast majority of the 2700 crowd drew their games today, generally without much adventure, even when they had the white pieces. In the lower-rated games, there was more action. Today’s winners were Magnus Carlsen (who parlayed an interesting opening idea into a dream ending against Aryan Tari), Vincent Keymer, Rasmus Svane, Peter Svidler, Daniele Vocaturo, Saleh Salem, Parham Maghsoodloo, Leinier Dominguez, Ivan Schitco (winning with Black against Radoslaw Wojtaszek - the guy is having a miraculous tournament so far), and Rameshbabu Praggnanandhaa. So that’s three of the 20 players rated 2700+ achieving wins (and one of them - Daniil Dubov - losing) while 6 of the 12 games without 2700s saw a decisive result.
Am I cherry-picking from a round that supports my conclusion? Admittedly, this is a small sample size, but I think I recall this happening in previous World Cups/FIDE K.O. World Championships as well, but someone enterprising should check this out. Not everyone engages in this sort of energy-saving approach - Carlsen and Veselin Topalov are clear exceptions - but my recollection is that it’s pretty common. Anyway, it’s fine by me, as a fan: there are still bound to be some exciting games each day until the numbers have dwindled down to the final eight (and probably the final four), and tiebreaks are always entertaining.
So, despite the many relatively peaceful games involving 2700s, there was still lots of entertainment, as you can see from this selection from today’s round (with my comments), here.