It is indeed wrong to assume that the mere replacement of existing forms of human labor by machines will lead to technological unemployment, but if the technology driving that replacement is advancing at a rapid rate; if it is built on a technological infrastructure that allows for winner takes all markets; and if ultimately it could lead to the development of human-like androids, then there is indeed reason to think that technological unemployment could happen. Since this will lead to a significant restructuring of human society, we should think seriously about its implications.
what you're atalking about is something that it will not happen before a very distante future, there is no reason to talk about that, unless you have a way to stay alive until then without being too old also
but we are already leading there, automation is growing each decade at least and it will grow as a even faster rate in the future
i'm all for it if we can earn without doing nothing, and the machines will work for us, in the sense that you can buy a robot that work for you
but the reaility will be actually different, probably akin to I Robot(that movie was great btw)