I know nothing about classical music but I'd have thought it easier having a skilled accompanist who could react if you went a touch wrong than playing to a recorded backup. I think it could provide a bit of a "safety net".

All I do know is that if on a very rare occasion I do find myself "stranded" as the only melody line in a tune in a session, I am very glad if there is for example a guitar player who knows what he's doing with the tune and will keep his accompaniment part going - I know someone like that can cover the odd blunder by me. I may still fail completely but I find something like that a confidence booster.