that's not true. Most important to Marx is the subjection of labor by capital, i.e., the control over the labor-process by capital, enforced by the reserve army of labor. It's this subjection (or domination or subsumption) that allows the capitalist to have control over what's produced and how it is produced, to impose his or her own vision of what's technical change on the world. Before that, they had to share power with craft-type workers, who had a different vision of what's technical change. (This is still true in some industries, i.e., parts of construction, though the subjection of labor is happening very quickly there.)
The subjection of labor -- made most real when machinery begins to be used to compete with living labor -- starts not with the market (which goes back thousands of years) but with proletarianization ("primitive" accumulation), in which the direct producers were separated from the means of production and subsistence and had to depend on the capitalists for their survival. This is when the modern capitalist reserve army of labor arose.
Market competition -- under capitalism, the competition of capitals -- is also important, since it (along with the constant structural tension arising from class antagonisms within production) pushes each capital "ahead," to introduce new technology, to develop new products, to survive. But this battle of competition is not the whole story for Marx.
> Your idea is that we can do OK on the detritus of
> capitalsit technology, but that presumes -- what --
> maintenance. I Guess we'd end up in a couple
> generations like Cuba, cannibalizing old cars and
> computers for parts. But stuff wears out. Asa
> technological society, this would not be sustainable.
The US blockade -- and Cuba's limited resources -- seem relevant to this anecdote and shouldn't be ignored.