Green’s Dictionary of Slang

soft, comfortable circumstances.

1930		S. Sassoon Memoirs of an Infantry Officer 268: There were times when I felt perversely indignant at the ‘cushiness’ of my convalescent existence.
1977		G. Melly Rum, Bum and Concertina (1978) 49: I’d been spoilt, softened by months of cushiness and tolerated skiving.
2005		CityBeat (Cincinnatti) 12 Jan. 🌐 Bush[...]’s always acted like the cushiness of his America was the same cushiness for the rest of us.