To counter that, the best sleeper train I ever took was from Beijing to Shanghai, and it felt like I'd travelled to the future (this was in 2008).

Second best might be Portland, OR to Sacramento, though I might have liked it if had been more like travelling to the past (I miss proper dining cars).

European ones have been cheap, cheerful, and uncomfortable, but this was 15 years ago for trips like Florence to Prague, IIRC.