After seven years (contracts expiring) both actors knew that playing hard ball could mean getting cut, and IIRC CBS has a history of not negotiating. Not too familiar with the show but apparently both characters were in potentially series exiting circumstances too. For an 8 season show, this move isn't actually uncommon, but they probably should've pay equality years ago.
Dae Kim has the show he co-created on ABC, he can probably shift to working on that full time.
And Scott Caan is the least memorable main cast member in the Ocean's films.
Dae Kim was a lead POV character on one of the most popular network shows of ALL TIME.
You can't pay THAT DUDE?
Really? It was big in the cultural discussion of the time, but in sheer viewers it's not even close to one of the most popular of all time.