If the proceeds weren't concentrated in few hands we could all benefit from mechanisation and the consequent increased production. As it stands, automating is plainly a direct threat to workers.
But there will be new sorts of work, at least partially in areas that we can't even think of right now, and there will also be increased leisure time. As long as we don't run out of natural/real resources and/or habitat (a BIG BIG if, mind you, and something I do feel legitimately pessimistic about- hard physical constraints to growth are a real thing), we'll find a way to muddle through.
What on earth makes you think that?
