You are basically claiming that a tractor or a machine replacing 25 farmers or factory workers with 1 is not a problem, but a computer replacing 25 tractor drivers with 1 computer operator is. I don't buy it.
Already broke this argument.
Farmers replaced with tractors moved to industrial sector, industrial workers replaced with CNC machinery were dumped to the services sector. But now there are simply no 4th sector to move in.
There was no such thing as industrial sector when farmers were around. There was no such thing as a white collar service sector, or IT sector, when CNC machinery was introduced. You don't know what the next sector will be, so there is no way you can definitively say that there is no 4th sector to move into.