That's not generally true in the US over the last 40 years, where the gains from productivity increases have been accumulated almost entirely by the top classes.
Yes, lower classes have access to many more conveniences then they might have had in earlier decades, but they are working far more hours, and their expected lifespan has started decreasing.
Yes, lower classes have access to many more conveniences then they might have had in earlier decades, but they are working far more hours, and their expected lifespan has started decreasing.