The way I see it, the problem is that the "any number of commercially available arms" - the models that are beyond absolute toys and might be waldoed to do work humans do today - are staggeringly expensive compared to the humans they might replace. The cheap arms are ... toys, they can do a nifty demo, but they are really shit for doing any actual work, and while there are also good arms available, they're so expensive that they're tricky to afford even for experimental useBut the expense of such is a product of the lack of demand for them. Cars (again) are produced with engines now having astoundingly good accuracy.
Of course, an accurate arm is going to always be expensive than a simple arm but cars, chips, phones and whatnot show that with large scale processes and heavy capital investment, accuracy and cheapness are compatible. But today, with software incapable of doing useful things with those arms, the people and institutions with the capital to make accurate robot arms cheap, through economies of scale, are not going to mobilize that capital.
just as we got the computer revolution not when we developed capable computers, but only after we developed affordable capable computers
Some technological advances happen through a feedback loop of commodities getting sold and producers improving those commodities (cars are an example here). Other technologies require a leap where a significant clump of capital has to be devoted to creating an advanced device for which there's no sellable (and sometimes no operable) device. (the biggest example of technological leap was the Manhattan project). It might be the case that things will happen that way with robots. But I'd also say it's an open question.
