What are the consequences if someone finds the accessible 1600-bit block $X$ and $R$-bit block $V$ such that $\text{Keccak-}f[1600](X \oplus V) = X$?
Then you've found a collision in SHA-3, and you get a prize.

There is a choice of prizes:


You could get your name on a virtual piece of paper that makes a lot of people excited and causes exceptionally insufferably tedious debates on Hacker News.
You could get a large number of unmarked bills in small denominations and possibly an unwanted piece of lead in your head by selling the collision on the black market.
You could get the fruit of exploiting the collision in real-world applications, with a lot more effort, and who has time for that kind of effort anyway?