Those are all tech that almost everyone owns. Makes sense that mass production would reduce costs and then the cost reductions would go towards zero. For new technology that hasn't been mass produced, it's a completely different story.
But the point was currently general-purpose humanoid robots is not affordable by the average person like say cars or washing machines currently are, but it will be because the costs will decrease. There was no argument that the price will forever keep going down, just like the price of cars or washing machines are not expected to constantly go down.
>> There was no argument that the price will forever keep going down
It's very hard for me to read the first quote as anything other than a continuing decrease in expected value of cost as a function of time. This directly contradicts the second quote.