One of the ways that Marx posited capitalist extract surplus value is to have the increase in quality of life always lagging the increase in efficiency. Our quality of life does increase, but only if capitalists are able to increase greater surplus value from our labor than that quality of life increase accounts for.
> don't forget that we're going to take down the world economy with it
Interestingly enough this is one of the major focuses of Capital vol III: the tendency of the rate of profit to fall.
Marx argued that eventually the Capitalist pressure to increase efficiency through automation means that while production continues to be more efficient, precisely because of this the ratio of profit to capital expended decreases. For Marx this was the ultimate threat to Capitalism itself.