I never get why elite players face each other when playing poker.

High rollers like the 100K PCA etc. are obviously very exciting, but I never get why pros want to play these.
The field is loaded with pros, so even the elite players will only have a very small edge.

Same goes for high stakes cash games. Was just watching Galfond, Sauce and Sigmond play PLO. Obviously these guys are at about the same skill level, so why would they play each other? They know that the chances of them going broke are pletty big, due to variance alone.

Maybe Zigmund is slightly less good, but it's still very close.

And I haven't even mentioned Isildur 9-tabling against Ivey, Antonius and Dwan, which is insane.

Do they just want to play? Is it because of staking, sponsorships/endorsements etc.?