Our western culture of individualism is older than capitalism. Much older. It stems from our agricultural and pastoral modes of production. Grains like wheat as well as livestock like sheep, goats, and cattle are highly amenable to work by an individual farmer or shepherd or rancher. Wheat is sown in ploughed fields that have been worked by oxen or horses.

Compare with a different grain like rice which must be transplanted into flooded fields by large groups of people or crops like potatoes or yams which must be planted and dug up individually by mass labour.

The structure of individualism or collectivism is in the roots of our cultures going back thousands of years. So rather than capitalism giving rise to individualism I think the opposite is the case.